Dynamically steered lidar adapted to vehicle shape

ABSTRACT

Dynamically steering a LIDAR to regions of a field of view with more information (e.g. the detailed boundaries of objects) is beneficial. Within embodiments a time target to complete a LIDAR scan of a FOV can be combined with sensor data from the local environment to generate laser steering parameters operable to configure a LIDAR to dynamically steer a laser beam within the course of a laser ranging scan. In this way, laser steering parameters based in part on a target time for a scan can function to tailor the density of laser ranging measurements to ensure that important objects are densely scanned while completing the laser ranging scan within the target time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US17/32585, filed May 15, 2017, which claims the benefit of priorityto each of: U.S. provisional patent application Ser. No. 62/337,867,filed on May 18, 2016; U.S. provisional patent application Ser. No.62/350,670, filed on Jun. 15, 2016; U.S. provisional patent applicationSer. No. 62/441,492, filed on Jan. 2, 2017; and U.S. provisional patentapplication Ser. No. 62/441,563, filed on Jan. 3, 2017.

BACKGROUND

In digital photography a charge-coupled-device CCD sensor can gatherlight from several million local directions simultaneously to generatedetailed images. In contrast, most laser range finders, such as a lightdetection and ranging system (LIDAR) scan or rotate laser beams andmeasure the time of flight (TOF) in much smaller number of directions.This sequential measurement approach limits the total number of rangemeasurements per second. Hence a LIDAR that scans a field of view (FOV)in a uniform deterministic manner can provide poor angular resolution.For example, consider a LIDAR with an angular range of 40 degreeselevation and 360 degrees azimuthal that is rotating at 10 Hz andgenerating 1 million laser measurements per second. If the measurementsare spread uniformly in the FOV (e.g. 40×360 degrees) the angularresolution would be 0.38 degrees in both the elevation and azimuthaldirections. At 50 m range from the LIDAR such an angular resolutionproduces range measurements with a spacing of 30 cm. This measurementspacing (i.e. angular resolution) can be insufficient for identifyingthe detailed boundaries of objects.

U.S. Pat. No. 9,383,753 to Templeton discloses a LIDAR with dynamicallyadjustable angular resolution, but only describes dynamic angularvelocity in a single axis for a rotating LIDAR. U.S. Pat. No. 9,383,753further assumes a rotating LIDAR and does not provide for arbitrarylaser orientation within a scan. U.S. Pat. No. 9,383,753 modifies theangular resolution of subsequent scans based on previous scans in partbecause the disclosed LIDAR has angular velocity that precludes rapiddirection reversals and changes. Hence, dynamically adapting LIDARmeasurement density within a scan, to improve the accuracy of objectboundary detection in the FOV remains a challenge.

SUMMARY

Embodiments of the present disclosure provide a laser range finder (e.g.a LIDAR) comprising one or more steerable lasers that non-uniformlyscans a FOV based on laser steering parameters. In a first group ofembodiments a method is provided to non-uniformly scan a FOV with aLIDAR by dynamically steering the LIDAR based on sensor data. Lasersteering parameters (e.g. instructions) are formulated using sensor datafrom the local environment. The laser steering parameters can functionto configure or instruct a steerable laser in a LIDAR to scan a FOV,with a dynamic angular velocity, thereby creating a complex shapedregion of increased or non-uniform laser pulse density during the scan.A plurality of important regions in a LIDAR FOV can be identified basedon a variety of types or aspects of sensor data (e.g. previous laserranging data or external data such as camera images, weather, GPS orinter-vehicle communication data). Such regions can be important becausethey contain information about boundaries of objects. Severalembodiments provide for scanning these important regions with anincreased laser pulse density in the course of a dynamically steeredlaser scan. In one aspect the proposed techniques are particularlyuseful for LIDAR on autonomous vehicles, which are often used inuncontrolled environments where an important object that warrants laserscanning with enhanced resolution, can exist in a wide variety oflocations within the FOV. In one example, first data from the localenvironment can be inter-vehicle communication data from a first vehiclethat causes a LIDAR in a second vehicle to obtain or generate a set oflaser steering parameters and dynamically steer or configure a laser ina LIDAR to non-uniformly scan a FOV.

In a related second group of embodiments a method to complete adynamically steered LIDAR scan of a FOV within a target time isdisclosed. A time target to complete a LIDAR scan of a FOV can becombined with sensor data from the local environment to generate lasersteering parameters operable to configure a LIDAR to dynamically steer alaser beam in the course of a laser ranging scan. In this way, lasersteering parameters based in part on a target time for a scan canfunction to tailor the density of laser ranging measurements to ensurethat the whole FOV or a defined portion of the FOV is scanned within thetarget time. During a first scan of the FOV a region of the FOV can beidentified. During a second scan of the FOV the identified region canreceive a dense scan with smaller point spacing than the average laserpulse spacing. The shape of the regions and the scan point density canbe selected based on requirements to complete the scan in a reasonabletime (e.g. a target time).

In a related third group of embodiment a method to dynamically configurea LIDAR by identifying objects or regions of interest in a FOV anddynamically apportioning LIDAR resources (e.g. number or density oflaser pulses), based on a number or relative importance of identifiedobjects is disclosed.

In one exemplary embodiment a laser range finding system obtains sensordata from an environment local to the LIDAR and thereby identifies aplurality of objects. The laser range finding system then assigns one ormore weights to each of the plurality of objects, wherein the weightsfunction to non-uniformly apportion laser range measurements in the FOVof the LIDAR. The laser range finding system uses the weights togenerate laser steering parameters (e.g. instructions to configure adynamically steerable laser in the LIDAR) and dynamically steers asteerable laser in the LIDAR according to the laser steering parameters.The method can thereby dynamically steer a LIDAR to generate anon-uniform density pattern of laser ranging measurements based on thenumber or relative importance of discovered objects.

In a fourth group of embodiments, a dynamically steered LIDAR can beconfigured based on the type (e.g. classification) of the localenvironment. Sensor data from the local environment can provide to aLIDAR a classification or location (e.g. a GPS location known to havemany bicyclists or a scene with camera data indicating the presence ofmany joggers). The sensor data (e.g. GPS data or Camera data) can beused to classify the local environment. In this way, classification ofthe local surroundings (e.g. an urban street versus a rural highway) canbe used to configure a dynamically steerable laser in a LIDAR to modifyor adapt laser steering to account for changing probabilities ofparticular hazards or occurrences. GPS data can be used to providelocation data. Laser steering parameters in portions of the FOV can bechosen based on the geographic location of a host vehicle. For example,in an urban (e.g. city) environment indicated by GPS data, lasersteering parameters can steer a steerable laser to regions of the FOVknown to be important for avoiding pedestrian accidents such ascrosswalks or corners. Similarly, the laser point density can beincreased at particular elevations where location-specific hazards areknown to exist, such as car sideview mirrors on narrow streets, deer onrural roads or trains at railroad crossings. In another example, GPSdata can indicating a geographic location known for rock slides can beused to steer the steerable laser in a laser range finder to increasethe laser point density in regions of the FOV that might contain rocks(e.g. the edge or corners of the road).

A fifth group of embodiments of the present disclosure provides a methodto dynamically steer a laser in a LIDAR and thereby progressivelylocalize the boundary of an object in the FOV. The method iterativelyscans the laser with a smaller point spacing in a region estimated tocontain a time-flight-boundary (e.g. an object edge) and therebyiteratively generating smaller regions wherein the boundary is estimatedin successive scans. Laser ranging data (e.g. times of flight) isanalyzed (e.g. processed to identify TOF boundaries) and the processedlaser ranging data is used to dynamically move or configure a steerablelaser so as to non-uniformly distribute some scan points into regionsestimated to contain more information (e.g. edges, boundaries,characteristic features). In another example, a dynamically steeredlaser range finder can react to very recent data, such as a large changein TOF between the last two laser reflections and use this data toperform a non-uniform scan spacing in a region between the two scanpoints. In this way the disclosed system can position the laser tobisect a region where the TOF exhibits a gradient. The point spacing andlaser location can be dynamically steered to investigate a region untilthe TOF gradient is sufficiently localized or until a maximum number ofiterations is reached. Hence this embodiment can improve boundarydetection within a scan or across several scans. In another embodiment acomputer could analyze some or all of the data from a scan and identifyone or more regions to receive an increased density of scan points or asmall laser spot size in a subsequent iteration.

In a sixth group of embodiments of the present disclosure a computer canestimate or classify an object in some or all of the FOV and can selecta non-uniform laser scan point distribution (e.g. a higher density in acomplex shaped region) based on the object classification. The laser canbe dynamically steered to perform the non-uniform scan pattern and theobject can be further identified based on the fit of the actual returnedlaser reflection with expected values. For example, an electronicallysteered laser LIDAR could perform a 1000 point scan of a FOV. The scancould initially be divided into 10 sweeps of the FOV, where each sweepis a 100 point grid and the sweeps are offset to generate the finalpoint cloud. On one of the 10 sweeps a computer coupled to orincorporated in the electronically steered LIDAR can identify an objectmoving in part of the FOV and can estimate that the object is a vehicle(i.e. an object classification of “vehicle”) is located in a portion ofthe FOV. The computer can select a non-uniform point distribution (e.g.a non-uniformly spaced sequence of laser measurements, based on a set oflaser steering parameters), based on the object classification, and usereflection data from the non-uniform sequence of laser pulses to testthe vehicle classification hypothesis. The disclosed classificationmethod can dynamically steer the laser to perform the non-uniform scanpoint pattern during the remainder of the scan. For example, uponidentification of an object and estimation of an object classification(e.g. classification=vehicle) sweeps 8,9,10 of the FOV can be devoted toperforming the dynamically-steered non-uniform portion of the scan.

Several embodiment of this disclosure provide methods for using sensordata generated from the FOV in order to guide a steerable-laser tolocations and regions containing the most data. Examples include lasersteering parameters based on object classification and estimated objectplacement, seeding the scan pattern of a future scan based on anestimate of object velocity (e.g. where to generate a densely scannedregion in a future scan of the FOV). Further examples of generatinglaser steering parameters for localized regions of the FOV (e.g. densescan regions) include using object detection or edge detection fromcameras.

In a seventh group of embodiments a LIDAR performs a progressiveboundary localization (PBL) method to determine the location oftime-of-flight (TOF) boundaries to within some minimum angular spacingin a FOV (i.e. progressively resolve the boundaries of objects inenvironment local to the LIDAR). The method can generate a sequence oflaser pulses, measure a corresponding sequence of laser reflections andmeasure a time of flight and direction corresponding to each of thelaser pulses. In response to identifying a nearest neighbor pair oflaser pulses within a range of directions for which the TOF differenceis greater than a TOF threshold, dynamically steering the LIDAR togenerate one or more intervening laser pulses with directions based onat least one of the nearest neighbor pair directions. The method cancontinue until all nearest neighbor pairs for which the TOF differenceis greater than a TOF threshold have an angular separation (i.e.difference in directions for the laser pulses in each pair) less than adirection threshold (e.g. less than 0.5 degrees direction difference).In this way a PBL method can localize the boundary by refining theangular ranges in which large changes in TOF occur until such ranges aresufficiently small.

In an eight group of embodiments a method to perform extrapolation-basedprogressive boundary localization method (EPBL) with a LIDAR isdisclosed. The method can use a LIDAR to find a first portion of aboundary in the FOV, extrapolate the direction of the boundary andthereby dynamically steer the LIDAR to scan in a second region of theFOV for the boundary. Hence the continuous and “straight-line” nature ofobject boundaries can be used to dynamically steer a LIDAR to scan theboundary. Similarly a classified object (e.g. a Van) can have apredicted boundary such that finding one part of the object andextrapolating or predicting a second portion of the object boundary(e.g. based on classification or a straight line edge in an identifieddirection) is used to dynamically steer a LIDAR scan. In one example, aLIDAR scans a first search region within a FOV, identifies a first setof locations or sub-regions of the first search regions that are locatedon or intersected by a TOF boundary (e.g. an object edge). The exemplaryEPBL method then extrapolates an estimated boundary location, outsidethe first search region, based on the first set of locations orsub-regions. The LIDAR then uses the estimated boundary location toconfigure or dynamically steer a laser within a second search region.The LIDAR can then process reflections form the second search region todetermine if the boundary exists in the estimated boundary location.

A ninth group of embodiments provides a low profile LIDAR system with avehicle-integrated laser distribution system. A laser beam from a LIDARcan be transmitted into a cavity region underneath a body panel of avehicle and thereby guided beneath the body panel (e.g. roof) to a lensoperable to transmit or refract the beam into a curtain of coveragearound the vehicle. The interior reflectors and lenses can form a laserbeam guide. The laser beam guide can augment the limited direct field ofview of a fully or partially embedded LIDAR by providing awell-controlled indirect beam path (e.g. requiring several reflections).The output laser angle from the beam guide is a function of the inputbeam angle from the LIDAR. In this way the beam guide can utilize andmodify existing cavities behind body panels that are common inautomotive design to guide and distribute laser beams for laser ranging.The beam guide can extend LIDAR coverage into hard to reach parts of theFOV (e.g. parts of the FOV obscured by the roof or sides of a vehicle)while allowing the LIDAR to remain low profile or embedded in thevehicle structure.

In a tenth group of embodiments a LIDAR can quickly evaluate a FOV byselecting and evaluating a plurality of smart test vectors operable toprovide early indications of important changes occurring in a FOV (e.g.a vehicle ahead changing lanes). Embodiments provides for improvedreaction times by dynamically steering a laser beam to firstly laserscan the set of test locations associated with the plurality of testvectors early in a scan of a FOV. Early scanning based on dynamicsteering of the laser is instead of gradually scanning the set of testpoint in the course of a uniform (i.e. non-dynamic) scan of the entireFOV. The results of one or more test vectors are used to obtain a set oflaser steering parameters to dynamically scan the field of view with anon-uniform laser pulse density. Hence test vectors can be used to planthe spatial distribution of laser ranging measurements and therebygenerate complex patterns of non-uniform measurement density in anupcoming scan. Test vectors can be based on defining features such asthe location of a wing mirror, edges, or lane position variation of avehicle. In some embodiments the scan is periodically interrupted toreacquire data from the test locations, reevaluate and update the testvectors.

Advantages

The techniques described in this specification can be implemented toachieve the following exemplary advantages:

Instead of generating a uniform laser pulse density throughout the FOV,the disclosed techniques provide for non-uniform laser pulse density bydynamically steering a laser based on data indicating the location ofimportant features in the FOV (e.g. boundaries of an object, a personrecognized in a digital image). This data-driven non-uniform laser pulsespacing has the further benefit of further localizing the importantfeatures. In another advantage the boundaries of objects in the FOV canbe progressively localized by refining laser steering parameters inregions of the FOV.

In another advantage the laser pulse density can be selected in variousparts of the FOV (e.g. left side, right side, or between −20 degrees and−30 degrees) based on aspects of the location of the laser range finder(e.g. the terrain, the GPS location, the time of day or a classificationfor the type of location such as urban or rural).

In a related advantage the disclosed techniques allow laser steeringparameters to encode for a wide variety of predefined high-density laserpulse patterns. Upon instructing or configuring a steerable laser withsuch laser steering parameters, the steerable laser can generate thecorresponding non-uniform pulse density region in the FOV. For example,a vehicle of model A with a dynamically steered laser range finder candevelop and share a library of laser point patterns effective to testthe hypothesis that a vehicle of model B is in the FOV. Using the one ofmore of the disclosed methods a vehicle of model A could estimate that avehicle of model B is present in the FOV, access a database of lasersteering parameters designed to test the hypothesis that the vehicle inthe FOV is of model B and configure a dynamically steerable laser togenerate a non-uniform laser pulse sequence to best test the hypothesisthat the vehicle is model B. Therefore the disclosed techniques enablecustomized laser pulse patterns to be generated, shared and used toguide a steerable laser range finder. The laser pulse patterns can becustomized to the geometry of vehicle model A and placement of thedynamically steered laser range finder. A dynamically steered rangefinder could be preprogrammed with a library of laser pulse patternscorresponding to the vehicle it is mounted on and placement on thevehicle.

The disclosed techniques can improve the cost effectiveness of a laserrange finder. A lower price laser range finder may have fewer lasers ora slower laser pulse rate. The disclosed techniques enable a laser rangefinder with a smaller total number of laser pulses per second todistribute those laser pulses in a dynamic and intelligently selectedmanner. Similarly, electronically steered LIDARs can often scan fewerpoints per second than a rotating LIDAR. The disclosed techniquesprovide for dynamically steering the electronically steered LIDAR toregions containing the most information in a data-driven manner.

The disclosed techniques can improve speed detection for objects in theFOV. The accuracy of speed detection in a laser range finding scan isrelated to the ability to accurately determine the object boundaryduring each scan. The disclosed techniques can estimate the boundarylocation and dynamically steer the laser to investigate the boundarylocation. The disclosed techniques enhance the speed of objectclassification, using boundary localization and dynamic laser pulsedensity selection.

DRAWINGS

FIGS. 1A and 1B are exemplary diagrams of a laser range finder and aplurality of laser pulse locations in a field of view, according to anembodiment of the present disclosure.

FIG. 2A illustrates a uniformly steered rotating LIDAR generating asequence of laser pulses in a field of view.

FIG. 2B-F illustrate dynamically steered LIDARs generating a variety ofnon-uniformly distributed sequences of laser pulses, according toembodiments of the present disclosure.

FIG. 3 is an exemplary diagram of a laser range finder and a non-uniformlaser pulse location distribution in a field of view, according to anembodiment of the present disclosure.

FIGS. 4A and 4B are functional diagrams illustrating several componentsof exemplary dynamically steered laser range finders in accordance withembodiments of the present disclosure.

FIG. 5 illustrates an exemplary laser range finding system including aprocessing subassembly and a dynamically-steerable laser assemblyconnected by a communication link, according to an embodiment of thepresent disclosure.

FIG. 6A-6D illustrate exemplary laser steering parameters according toan aspect of the technology.

FIG. 7 illustrates a process for iteratively improving laser steeringparameters and object boundary estimation according to aspects of thetechnology.

FIG. 8 illustrates exemplary object boundary estimation based ondynamically steering a laser range finder, according to an embodiment ofthe present disclosure.

FIG. 9 is a functional diagram illustrating several components of anexemplary dynamically steered laser range finder in accordance with anembodiment of the present disclosure.

FIG. 10A-10D illustrates flow diagrams of processes for selecting lasersteering parameters and dynamically steering a laser range finder,according to embodiments of the present disclosure.

FIG. 11 illustrates a flow diagram of a process of refining a set oflaser steering parameters based on measured data, according to anembodiment of the present disclosure.

FIG. 12A-12B illustrates flow diagrams of processes for selecting lasersteering parameters based on classification, according to an embodimentof the present disclosure.

FIG. 13 illustrates several aspects of a progressive boundarylocalization method.

FIG. 14A-14B illustrate several aspects of a progressive boundarylocalization method.

FIG. 15 illustrates several aspects of a progressive boundarylocalization method.

FIG. 16 illustrates several aspects of a progressive boundarylocalization method.

FIG. 17A-17F illustrate several aspects of a progressive boundarylocalization method.

FIG. 18 illustrates several aspects of an extrapolation-basedprogressive boundary localization method.

FIG. 19 illustrates several aspects of an extrapolation-basedprogressive boundary localization method.

FIG. 20 illustrates an exemplary laser range finding system operable togenerate pulsed laser range finding and an exemplary laser range findingsystem operable to generate a continuous wave laser beam.

FIG. 21A illustrates a laser LIDAR with an associated field of viewaccording to an aspect of the present disclosure.

FIGS. 21B and 21C illustrate several placements of a LIDAR relative to avehicle and the associated impact of placement on aspects of the fieldof view, according to an aspect of the present disclosure.

FIG. 21D is an exemplary diagram of an integrated laser distributionsystem, embedded in the roof of a vehicle, including a laser rangefinder and a laser beam guide, according to an embodiment of the presentdisclosure.

FIGS. 21E and 21F are exemplary diagrams of vehicle-integrated laserdistribution systems, attached to the roof of a vehicle, including alaser range finder and a beam guide, according to an embodiment of thepresent disclosure.

FIGS. 22A, 22B and 22C illustrates several exemplary beam guidesaccording to several embodiments of the present disclosure.

FIG. 23 is an exploded view of a variety of components of avehicle-integrated laser distribution system in accordance with anembodiment of the present disclosure.

FIG. 24A illustrates a plurality of planes, each representing directionsalong which the indirect reflections from objects that are outside thedirect FOV of a laser LIDAR can be provided to the LIDAR using variouscomponents of a vehicle-integrated laser distribution system inaccordance with an embodiment of the present disclosure.

FIG. 24B illustrates a plurality of planes, each representing directionsalong which the indirect reflections from objects that are outside thedirect FOV of a laser LIDAR can be provided to the LIDAR using variouscomponents of a vehicle-integrated laser distribution system inaccordance with an embodiment of the present disclosure.

FIG. 25 is a block diagram of several components of an integrated laserdistribution system, according to an embodiment of the presentdisclosure.

FIG. 26 is a diagram of several laser beam paths in an integrated laserdistribution system, according to an embodiment of the presentdisclosure.

FIG. 27A is an exemplary diagram of an vehicle-integrated laserdistribution system, embedded in the roof of a vehicle, including alaser range finder and a beam guide, according to an embodiment of thepresent disclosure.

FIGS. 27B and 27C illustrate an exemplary vehicle-integrated laserdistribution system, with wide azimuthal coverage at low elevationangles, embedded in the roof of a vehicle, according to an embodiment ofthe present disclosure.

FIG. 28 is an exemplary diagram of a vehicle-integrated laserdistribution system behind the bumper/hood panels of a vehicle andproviding an indirect field of view to a LIDAR.

FIGS. 29A and 29B illustrate a process for providing a laser rangefinder with extended coverage using a vehicle mounted beam guideaccording to aspects of the technology.

FIGS. 30A and 30B illustrate several aspects of a laser ranging systemwith a dynamically positioned aperture based on the location ofreflected laser beams in the field of view of a photodetector.

FIG. 31 illustrate several aspects of a laser ranging system with adynamically positioned aperture based on the location of reflected laserbeams in the field of view of a photodetector.

FIG. 32 illustrates several apertures that can be dynamically generatedbased on the position of a laser beam in a field of view of aphotodetector.

FIG. 33 is a functional diagram illustrating several components of anexemplary laser range finder in accordance with an embodiment of thepresent disclosure.

FIG. 34 illustrates a method for generating an aperture in a spatiallight modulator based on data indicating the location of a laser beam ina field of view.

FIG. 35 is an exemplary diagram of a laser range finder and a pluralityof laser pulse locations in a field of view, according to an embodimentof the present disclosure.

FIG. 36A-36C illustrate methods for steering a laser based on a keepoutregion, according to an embodiment of the present disclosure.

FIG. 37 illustrates a keepout mask circuit operable to receive signalsbased on one or more keepout areas and to provide a masked input signalto a laser transmitter.

FIGS. 38A, 38B and 38C illustrate various views of a solid state LIDARwith an attached adapter to divert laser beams in a portion of thedirections in the field of view into beam guides, thereby enablingindirect ranging in accordance with an embodiment of the presentdisclosure.

FIG. 39 illustrates a field of view of a LIDAR, with a direct field ofview and an indirect field of view providing laser reflections fromseveral regions associated with the vehicle outside of the rangingregion provided by direct line of site of the LIDAR.

FIG. 40 illustrates several components to provide direction feedbackcontrol of an electronically steered LIDAR, in accordance with anembodiment of the present disclosure.

FIG. 41 illustrates several components of an electronically steed LIDARwith a selective light modulator, in accordance with an embodiment ofthe present disclosure.

FIG. 42 illustrates a plurality of test regions associated with anelephant in the field of view of a laser range finding system inaccordance with an embodiment of the present disclosure.

FIG. 43 illustrates a several exemplary sets of laser steeringparameters, a set of test locations, a set of test data, a set of rulesand a set of test results, according to an embodiment of the presentdisclosure.

FIGS. 44A and 44B is an exemplary diagram illustrating the applicationof an exemplary scan planning method by a laser range finding system inaccordance with an embodiment of the present disclosure.

FIGS. 45A, 45B, 45C, 45D and 45E illustrate a variety of steps of anexemplary laser scan planning method in accordance with an embodiment ofthe present disclosure.

FIG. 46A illustrates test data gathered from a uniformly distributed setof test locations in a field of view, in accordance with an embodimentof the present disclosure.

FIG. 46B illustrates test data gathered from a non-uniformly distributedset of test locations in a field of view, in accordance with anembodiment of the present disclosure.

FIG. 47 illustrates a flow diagram of a process of generating anon-uniform scan of a field of view based on processing test data from aset of test locations, according to an embodiment of the presentdisclosure.

FIG. 48A illustrates a flow diagram of a process of generating anon-uniform scan of a field of view based on processing test data from aset of test regions, and thereby updating the test regions, according toan embodiment of the present disclosure.

FIG. 48B illustrates a flow diagram of a process of generating anon-uniform scan of a field of view based on periodically gathering testdata from a set of test regions, and thereby updating set of lasersteering parameters used to generate the non-uniform scan, according toan embodiment of the present disclosure.

FIG. 49 illustrates an exemplary laser ranging scan performed accordingto an embodiment of the present disclosure.

FIG. 50 illustrates a flow diagram for an exemplary method for laserscan planning using time of flight measurements, according to anembodiment of the present disclosure.

DETAILED DESCRIPTION

In digital photography light from is received at a sensor form manypoints in the local environment at once. In contrast, a laser rangefinder can use a relatively small number of lasers (e.g. 1-64) togenerate laser pulses aimed sequentially at a number of points (e.g.100,000) to perform laser ranging scans of the FOV. Hence, the laserpulses (e.g. and corresponding time of flight measurements in discretedirections) represent a scarce resource and the FOV is oftenundersampled with respect to sensing detailed boundaries of objects inthe local environment. Many LIDARs mechanically rotate with a constantor nearly constant angular velocity. Such rotating LIDARs can sweep oneor more lasers through a deterministic range of directions (e.g. eachlaser sweeping through a 360 degree azimuthal range at a fixed elevationangle). This type of operation does not constitute dynamically steeringthe laser(s) in a LIDAR. The angular momentum of the spinning portion ina mechanical LIDAR prevents rapid changes in angular velocity. Eachlaser in a mechanical LIDAR can generate a uniformly spaced sequence oflaser pulses in a 1-D angular range. The angular velocity can beselected for many mechanical LIDAR (e.g. 5-20 Hz for the HDL-64E fromVelodyne Inc. or Morgan Hill, Calif.), but remains constant from onerotation to the next.

A uniform scan of the entire FOV is simple and somewhat inherent inrotating LIDARS, but is sub-optimal for gathering the most informationfrom the FOV. For example, large sections of the FOV (e.g. Walls androads) can return a predictable, time invariant, homogeneous response. Amodern LIDAR can scan over 2 million points per second. Hence oneembodiment of the present technology tries to select the 2 million scanpoints with the most information (e.g. edges or boundaries) by steeringthe laser in a dynamic manner.

Recently, advancements in electronically-steerable lasers and phasedarray laser beam forming have made it possible to dynamically steer alaser within a FOV. A steerable laser can be mechanically-steerable(e.g. containing moving parts to redirect the laser) orelectronically-steerable (e.g. containing an optical phased array toform a beam at in one of many directions). For the purpose of thisdisclosure a steerable laser is a laser assembly (e.g. includingpositioning components) that can change the trajectory or power level ofa laser beam. For the purpose of this disclosure a steerable laser isdynamically steerable if it can respond to inputs (e.g. user commands)and thereby dynamically change the power or trajectory of the laser beamin the course of a scan of the FOV. For the purpose of this disclosuredynamically steering a laser is the process of providing input data(e.g. instructions such as laser steering parameters) to a steerablelaser that causes the laser to dynamically modulate the power ortrajectory of the laser beam during a scan of the FOV. For example, alaser assembly that is designed to raster scan a FOV with a constantscan rate (e.g. 10 degrees per second) and pulse rate (e.g. 10 pulsesper second) is not being dynamically steered. In another example, theprevious laser assembly can be dynamically steered by providing inputsignals and circuitry that dynamically changes the angular velocity ofthe laser assembly to generate non-uniformly spaced laser pulses in theFOV, based on the input signals (e.g. thereby generating an image on asurface in the FOV). A trajectory change can be a direction change (i.e.a direction formed by a plurality of pulses) or a speed change (i.e. howfast the laser is progressing in a single direction across the FOV). Forexample, dynamically changing the angular speed across a FOV of a pulsedlaser with a constant direction causes the inter-pulse spacing toincrease or decrease thereby generating dynamically defined laser pulsedensity.

In the context of the present disclosure most rotating LIDAR do notcomprise dynamically steerable lasers since neither the power nor thetrajectory of the laser beam is dynamically controllable within a singlescan. However a rotating or mechanical LIDAR can be dynamically steered.For example, by providing input data that causes the laser todynamically vary the laser pulse rate within a scan of the FOV, sincethe net result is a system that can guide or steer the laser to producea non-uniform density laser pulse pattern in particular parts of theFOV.

Recently, electronically scanned LIDAR such as the model S3 fromQuanergy Inc. of Sunnyvale, Calif. have been developed. Thesesolid-state electronically scanned LIDAR comprise no moving parts. Theabsence of angular momentum associated with moving parts enables dynamicsteering of one or more lasers in electronically scanned solid-stateLIDAR systems.

In many laser range finding systems the laser is periodically pulsed andthe exact pulse location in the FOV cannot be controlled. Neverthelesssuch a periodic pulse laser can be used with the present disclosure toproduce a complex shaped region of higher pulse density than the areasurrounding the region by increasing the laser dwell time within theregion. In this way a periodically pulsed laser will produce a greaterdensity of pulses in the complex shaped region of a FOV. For the purposeof this disclosure a complex shaped region is a region having acomplex-shaped perimeter such as a perimeter with more than fourstraight edges or a perimeter with one or more curved portions and twoor more distinct radaii of curvature. Exemplary complex-shaped regionsare, a region with a pentagonal perimeter, a hexagonal perimeter anelliptical perimeter or a perimeter capturing the detailed outline of acar. Other laser range finding systems transmit a continuous lasersignal, and ranging is carried out by modulating and detecting changesin the intensity of the laser light. In continuous laser beam systemstime of flight is directly proportional to the phase difference betweenthe received and transmitted laser signals.

In one aspect the dynamically steered laser range finder can be used toinvestigate a FOV for boundaries associated with objects. For example, asmall shift in the position of the LIDAR laser may identify a largechange in TOF associated with the edge of an object 100 ft away. Incontrast RADAR has much greater beam divergence and hence a much widerspot size impacts the object (often many times the object size). Hencethe reflections from beam scanned RADAR represent the reflections frommany points on the object, thereby making beam steered RADAR useful forobject detection but impractical for performing detailed boundarylocalization. Hence, due in part to the large beam divergence of RADARbeams, a small change in radar beam direction can provide little if anyactionable information regarding the edges of an object. In contrast thespot size of the laser remains small relative to the boundary of manyimportant objects (people, dogs, curbs). The present technology canenable the boundaries (e.g. edges) of objects to be dynamicallydetermined by a process of iteratively refining the scan points for theelectronically steered LIDAR. For example, the LIDAR can use a bisectionalgorithm approach to iteratively search for the boundary of apedestrian in the FOV. The LIDAR could first receive an indication thatpoint P1 in a point cloud has a TOF consistent with the pedestrian andcan scan iteratively to the right and left of P1 with decreasing angularrange (e.g. in a bisection approach) to estimate the exact location ofthe boundary between the pedestrian and the surrounding environment. Ingeneral, this technique can be used to dynamically configure a laser ina LIDAR to investigate changes in TOF within a point cloud toiteratively improve boundary definition.

FIG. 1A illustrates a laser range finder system 105 (e.g. a LIDAR) thatcomprises a steerable laser assembly 115. Steerable laser assembly 115scans one or more a lasers (e.g. steerable laser 121) within a field ofview FOV 130. The field of view 130 can be defined by an azimuthal (e.g.horizontal) angular range 140 and an elevation (e.g. vertical) angularrange 145. Steerable laser 121 scans FOV 130 and generates a pluralityor sequence of laser pulses, (e.g. laser pulses 150 a, 150 b and 150 c)in a sequence of directions. The direction in the FOV of the each of theplurality of laser pulses is illustrated with a “+” symbol. Some of thelaser pulses (e.g. 150 a and 150 b) can be reflected by objects (e.g.person 160 and vehicle 170). In the embodiment of FIG. 1A the laserpulses are evenly spaced in the FOV, such that the angular separationbetween neighboring laser pulses is a constant value in one or both ofthe horizontal and vertical directions. Accordingly, only a few of thelaser pulses (e.g. 5-6 pulses) reflect from each of the objects 160 and170 due in part to the uniform laser pulse density throughout the FOV.For the purpose of this disclosure the FOV of laser range finder 110 canbe defined as the set of all directions (e.g. combinations of elevationand azimuthal angles) in which the laser range finder can perform laserranging measurements.

FIG. 1B illustrates a laser range finder 110, with a steerable laserassembly 120 that scans a steerable laser 121 in the same FOV 130 togenerate approximately the same number of laser pulses. In the exampleof FIG. 1B the steerable laser is dynamically steered (instead ofuniformly or non-dynamically steered) to generate a non-uniform highlaser pulse density pattern surrounding the boundaries 180 and 190 orperson 160 and vehicle 170 respectively. Steerable laser assembly 120 isan example of a dynamically-steerable laser assembly and can comprisecircuitry to dynamically accept instructions (e.g. laser steeringparameters) and configure laser 121 to rapidly change direction or pulserate of a laser beam. Several embodiments of the present technologyprovide for using laser steering parameters to dynamically steer, guide,instruct or configure a steerable laser (e.g. an electronicallysteerable laser) to generate regions of increased laser pulse density ornon-uniform pulse density. Laser range finder 110 can further comprise alaser detector 122 to detect reflections from laser pulses.

FIG. 2A illustrates some of the features and characteristics of arotating LIDAR that is not dynamically steered (e.g. the HDL-64e fromVelodyne Inc. or Morgan Hill, Calif.). Rotating LIDAR 205 has two lasers210 a and 210 b each having a fixed corresponding elevation angle 215 aand 215 b. The lasers are mechanically rotated in azimuthal direction218 (i.e. sweeps the azimuthal angle from 0-360 degrees). Lasers 210 aand 210 b rotate at a constant angular velocity and have a constantpulse rate. Each laser thereby produces a corresponding uniformly spacedsequence of laser pulses (e.g. sequence 222) with a constant elevationangle. The lasers proceed across FOV 220 in a predictable manner witheach laser pulse in a sequence having a direction that is separated fromthe immediately previous laser pulse by a constant angular separation inthe azimuthal plane. In particular, the lasers are not reconfiguredduring each scan to dynamically vary either the angular velocity or thepulse rate. For example, each laser pulse in sequence 222 has adirection that can be can be uniquely defined in spherical coordinatesby an elevation angle (sometimes called a polar angle) and an azimuthalangle. In the case of sequence 222 each laser pulse has a constantelevation angle 215 b and uniformly spaced azimuthal angles. In the caseof FIG. 2A the range of azimuthal angle separations from one laser pulseto the next (e.g. angular separation 223) is single value.

In contrast FIG. 2B illustrates a LIDAR 207 that is dynamically steeredby modulating the pulse frequency of a laser while rotating the laser ata constant angular velocity. The result of configuring laser 210 a todynamically modulate the pulse frequency is a sequence of laser pulses224 with directions in a 1-D range that are separated by varyingamounts. In the case of FIG. 2B the direction separations from one laserpulse to the next (e.g. angular separation 223) have a 1-D range andhence LIDAR 207 is dynamically steered in a 1 dimension. The directionsin sequence 224 span a 1-D range.

In FIG. 2C an electronically steered LIDAR 230 is dynamically steered bymodulating the angular velocity of laser 235 while maintaining aconstant pulse rate. The result of configuring the electronicallysteerable laser to dynamically modulate the angular velocity (orposition of the laser in the FOV 236) is a sequence 238 of laser pulseswith directions in a 1-dimensional range that are separated by varyingamounts. FIG. 2C illustrates dynamically steering a laser including atleast three different velocities in the course of a single sweep of theFOV including an initial nominal velocity followed by slowing down thelaser trajectory to group pulses more closely and then followed byspeeding up the laser to separate laser pulses by more than the nominalseparation.

FIG. 2D illustrates dynamically steering a laser in 2 dimensions togenerate a sequence of laser pulses that span a 2-D angular range. Theresulting sequence has a 2-D angular range from a single laser, incontrast to a rotating LIDAR where each laser generates a sequence witha 1-dimensional angular range. A LIDAR can be configured to dynamicallysteer a laser to produce sequence 240 by dynamically controlling theangular velocity or position of the laser in 2 dimensions (e.g. bothazimuthal and elevation). Such a sequence cannot be performed by arotating LIDAR due in part to the angular momentum of the rotatingcomponents preventing fast modulation of the elevation angle above andbelow azimuthal plane.

FIG. 2E illustrates dynamically steering a laser to generate a sequenceof laser pulses, including several direction reversal during thesequence. For example, laser pulse sequence 242 begins by progressingthe laser from left to right across the FOV 244. After laser pulse 245the laser is reconfigured to reverse the X component of the laserdirection from the positive X direction to the negative X direction.After laser pulse 246 the laser is configured to reverse direction again(i.e. back to a positive X direction). In contrast to merely modulatingthe speed of laser 235 in the positive X direction, direction reversalsenable a dynamically steered laser to scan back and forth across adiscovered boundary. In addition 2-D dynamic steering combined withdirection reversal in the course of a scan of FOV 244 enables laser 235to dynamically scan along a complex shaped boundary of an object.

FIG. 2F illustrates dynamically steering a steerable laser (e.g.electronically steerable laser 235 in FIG. 2E) to generate a sequence oflaser pulses 250 that generate a complex (e.g. spiral) shape. Complexsequence 250 is not possible with a LIDAR that is not dynamicallysteered (e.g. a LIDAR that that merely rotates around a single axis).One advantage of generating a complex shaped sequence with non-uniformspacing is the ability to arbitrarily determine the order in whichportions of the FOV 255 are scanned. For example, sequence 250 mayeventually scan a similar region with a similar density as a rotatingLIDAR but has the advantage of scanning the outer perimeter first andthen gradually progressing towards the center of FOV 255.

FIG. 3 illustrates dynamically steering laser 121 in FOV 130 to generatetwo dense scan regions 310 a and 310 b, each with increased density oflaser pulses (e.g. laser pulse 150 d) relative to the average pulsedensity in the remainder of the FOV 130. In other embodiments dynamicsteering can generate dense scan regions with greater laser pulsedensity (i.e. the number of laser measurements or pulses per unit solidangle) relative to an immediately surrounding area, relative to theaverage laser pulse density for a FOV, or relative to a previous scan ofthe same or a similar region. A solid state LIDAR 305 can perform adynamically steered scan of a FOV by firstly identifying an object inthe FOV (e.g. based on uniform low density scan of the FOV). Secondly, asteerable laser assembly 120 can receive laser steering parameters (e.g.instructions or configuration parameters) operable to generate increasedlaser pulse density in a region (e.g. 310 a) surrounding the detectedobject. Laser steering parameters can generate a uniform shaped densescan region (e.g. 310 a), such as a square, rectangle or circle.Alternatively, the laser steering parameters can generate a more complexshaped dense scan region (e.g. 310 b). Laser steering parameters thatgenerate a uniform-shaped dense scan region such as 310 a can be usefulwhen the boundary of the object is unknown. (e.g. boundary 180 of person160 in FIG. 1B)

Conversely, when the location of the boundary of an object is known withsome degree of accuracy a set of laser steering parameters can beselected to instruct or configure the steerable laser to generate a morecomplex dense scan region (e.g. 310 b) that is smaller, yet stillcontains the boundary. For example, the boundary 190 of vehicle 170 inFIG. 1B can be estimated from a previous laser scan data to lie betweenan outer perimeter 320 and an inner perimeter 330. Laser steeringparameters can be selected to configure steerable laser 121 to perform adense scan in the intervening region 310 b. The ability of the densescan regions 310 a and 310 b to encompass the boundary can easily beverified by a reflection detector operable to measure aspects of thetime-of-flight or laser intensity of reflected pulses. In one embodimenta scan of FOV 130 by LIDAR 305 can comprise a first portion coveringsome or all of the FOV at a nominal laser pulse density followed byconfiguring the steerable laser to dynamically steer and thereby scanone or more dense scan regions with a greater laser pulse density. Thedynamic steering can generate a laser pulse sequence within each densescan region that includes 2-D direction changes and direction reversals.

Dynamically Steered Laser Range Finder

FIG. 4A illustrates several components of an exemplary dynamicallysteered laser range finder 405 in accordance with an embodiment of thisdisclosure. Laser range finder 405 can contain a steerable laserassembly 406. Laser range finder 405 can contain a laser steeringparameter generator 410 to receive sensor data and generate lasersteering parameters based on the sensor data. Sensor data can bereceived from sensor data processor 475 or directly from a sensor.Sensor data can indicate one or more aspects of the local environment.Laser steering parameter generator 410 can function to generate lasersteering parameters (e.g. instructions) and transmit the parameters tothe steerable laser assembly 406. Laser steering parameter generator 410can transmit the parameters in a timed manner, such that upon receivingeach laser steering parameter the steerable laser assembly 406 executesor reacts to the laser steering parameter. Alternatively, laser steeringparameters can be transmitted in a batch or instruction file that isexecuted over a period of time by the steerable laser assembly 406.

Steerable laser assembly 406 can comprise one or more laser generators420 and a laser positioner 430. The one or more laser generators 420(often shortened to “lasers”) can be laser diodes to produce one or morelaser beams (e.g. beam 435) at one or more locations in the FOVdetermined by the laser positioner 430. Laser positioner 430 functionsto steer one or more laser beams (e.g. beam 435) in the FOV based on thelaser steering parameters. Laser positioner 430 can mechanically steer alaser beam from laser generator 420. Rotating LIDARs often use amechanically steered laser positioner. An exemplary mechanically steeredlaser positioner 430 can include mechanical means such as a steppermotor or an induction motor to move optical components relative to theone or more laser generators. The optical components in an exemplarymechanical laser positioner can include one or more mirrors, gimbals,prisms, lenses and diffraction grating. Acoustic and thermal means havealso been used to control the position of the optical elements in thelaser positioner 430 relative to the one or more laser generators 420.Laser positioner 430 can also be a solid state laser positioner, havingno moving parts and instead steering an incoming laser beam usingelectronic means to steer the laser beam in an output direction withinthe FOV. For example, an electronically steerable laser assembly canhave a solid state laser position comprising a plurality of opticalsplitters (e.g. Y-branches, directional couplers, or multimodeinterference couplers) to split an incoming laser beam into multipleportions. The portions of the incoming laser beam can then betransmitted to a plurality of delay line where each portion is delayedby a selectable amount (e.g. delaying a portion by a fraction of awavelength). Alternatively the delay lines can provide wavelength tuning(e.g. selecting slightly different wavelengths from an incoming laserbeam). The variable delayed portions of the incoming laser beam can becombined to form an output laser beam at an angle defined at least inpart by the pattern of delays imparted by the plurality of delay lines.The actuation mechanism of the plurality of delay lines can bethermo-optic actuation, electro-optic actuation, electro-absorptionactuation, magneto-optic actuation or liquid crystal actuation. Laserpositioner 430 can be combined with one or more laser generators 420onto a chip-scale optical scanning system such as DARPA's Short-rangeWide-field-of-view extremely agile electronically steered PhotonicEmitter (SWEEPER). Laser positioner 430 can also be one or moreelectromechanically mirrors such as the array of electromechanicalmirrors disclosed in U.S. Pat. No. 9,128,190 to Ulrich et al. For thepurpose of this disclosure a steerable laser assembly (e.g. 406 in FIG.4A) is considered a dynamically steerable laser assembly if the laserpositioner (e.g. positioner 430) can dynamically steer laser pulses inthe course of a scan of a field of view. In some embodiments adynamically steerable laser assembly has a laser positioner thatcomprises circuitry to process instructions (e.g. laser steeringparameters) during a scan of a FOV and a reconfigurable mechanical orelectronic tuning portion to direct one or more laser pulses during thescan. For example, a steerable laser assembly can have 64 lasers and alaser positioner comprising a simple rotating mirror. In contrast adynamically-steerable laser assembly may have 64 lasers and a opticalbeam steering array operable to steer laser pulses form each of thelasers dynamically based on a stream of instructions (e.g. lasersteering parameters) provided during a scan of a FOV.

Laser range finder 405 can further comprise a ranging subassembly 438.Ranging subassembly 438 can have a detector 440 that can comprise aphotodetector 450 (e.g. photodiodes, avalanche photodiodes, PIN diodesor charge coupled devices CCDs, single photon avalanche detectors(SPADs), streak cameras). Photodetector 450 can also be a 2Dphotodetector array such as a CCD array or an InGaAs array. Detector 440can further comprise, signal amplifiers and conditioners 452 (e.g.operational amplifiers or transconductance amplifiers) to convertphotocurrent into voltage signals, Ranging subassembly 438 can furthercomprise circuitry such as a time of flight calculator circuit 455 (e.g.a phase comparator) and an intensity calculator 460. The construction ofthe steerable laser assembly 406 can co-locate detector 440 andsteerable laser assembly 406 such that detector 440 is pointed in thedirection of the outgoing laser beam and can focus the detector on anarrow part of the FOV where the reflected light is anticipated to comefrom.

Steerable laser assembly 406 can contain a time of flight calculator 455to calculate the time of flight associated with a laser pulse strikingan object and returning. The time of flight calculator 455 can alsofunction to compare the phase angle of the reflected wave with the phaseof the outgoing laser beam and thereby estimate the time-of-flight. Timeof flight calculator 455 can also contain an analog-to-digital converterto convert an analog signal resulting from reflected photons and convertit to a digital signal. Laser range finder 405 can contain an intensitycalculator 460 to calculate the intensity of reflected light. Laserrange finder 407 can further comprise a 3D location calculator 464 tocalculate a 3D location associated with a laser reflection 445.

Laser range finder 405 can contain a data aggregator 465 to gatherdigitized data from time of flight calculator 455 and intensitycalculator 460 or 3D location calculator 464. Data aggregator 465 cangroup data into packets for transmitter 470 or sensor data processor475. Laser range finder 405 can contain a transmitter 470 to transmitdata packets. Transmitter 470 can send the data to a processingsubassembly (e.g. a computer or a remote located sensor data processor)for further analysis using a variety of wired or wireless protocols suchas Ethernet, RS232 or 802.11.

Laser range finder 405 can contain a sensor data processor 475 toprocess sensor data and thereby identify features or classifications forsome or all of the FOV. For example, data processor 475 can identifyfeatures in the FOV such as boundaries and edges of objects usingfeature identifier 480. Data processor 475 can use feature localizer 485to determine a region in which the boundaries or edges lie. Similarly aclassifier 490 can use patterns of sensor data to determine aclassification for an object in the FOV. For example, classifier 490 canuse a database of previous objects and characteristic features stored inobject memory 495 to classify parts of the data from the reflectedpulses as coming from vehicles, pedestrians or buildings. In theembodiment of FIG. 4A sensor data processor 475 is located close to thesteerable laser assembly (e.g. in the same enclosure), thereby enablingprocessing of the sensor data (e.g. reflection ranges) without the needto transmit the reflection data over a wired or wireless link. FIG. 4Ais an example of an embedded processing architecture where the latencyassociated with a long distance communication link (e.g. Ethernet) isavoided when transmitting range data to the sensor data processor.

FIG. 4B illustrates several components of a dynamically steered laserrange finder 407 in accordance with an embodiment of this disclosure. Inthis embodiment the data processing and laser steering parametergeneration components are remotely located from the steerable laserassembly 406. Steerable laser assembly 406 can contain one or morelasers (e.g. laser generator 420), and a positioner 430, that caninclude circuitry to dynamically steer a laser beam from the lasergenerator based on processing laser steering parameters. Laser rangefinder 407 can contain a receiver 415 to receive laser steeringparameters from the remotely located laser steering parameter generator410. Receiver 415 can be a wired or wireless receiver and implement avariety of communication protocols such as Ethernet, RS232 or 802.11.Transmitter 470 can transmit data from the time of flight calculator 455intensity calculators and 3D location calculator 464 (in FIG. 4A) to aremote located data aggregator 465.

FIG. 5 illustrates several components of a laser range finder 510according to several embodiment of the present disclosure. Laser rangefinder 510 can contain a processing subassembly 520, adynamically-steerable laser assembly 505 and a communication link 530for linking the processing and steerable laser assemblies. Processingsubassembly 520 can include one or more processors (e.g. sensor dataprocessor 475 in FIGS. 4A and 4B) one or more transceivers (e.g. atransceiver including receiver 415 and transmitter 470) such as anEthernet, RS485, fiber optic, Wi-Fi, Bluetooth, CANBUS or USBtransceiver. Processing subassembly 520 can also include acomputer-readable storage medium (e.g. flash memory or a hard diskdrive) operable to store instructions for performing a method to detectand utilize a remote mirror (e.g. a roadside mirror).Dynamically-steerable laser assembly 505 can include a laser generator420 and a laser positioner 430 to steer a laser beam at one or morelocations in the FOV based on the laser steering parameters. Laserpositioner 430 can include one or more optical delay lines, acoustic orthermally based laser steering elements. In a solid state steerablelaser assembly laser positioner 430 can function to receive instructions(e.g. laser steering parameters) and thereby delay portions of a laserbeam (i.e. create a phase difference between copies of the laser beam)and then combine the portions of the laser beam to form an output beampositioned in a direction in the FOV. A mechanical laser positioner 430can be a mirror and mirror positioning components operable to receiveinput signals (e.g. PWM input to a steeper motor) based on lasersteering parameters and thereby steer the mirror to position a laser ina direction in the FOV. Steerable laser assembly 505 can also include adetector 440 comprising components such as light sensor(s) 450, time offlight calculator 455 and light intensity calculator 460 and 3Dlocation. Steerable laser assembly 505 can include one or moretransceivers (e.g. receivers 415 and transmitters 470) such as Ethernet,RS485, fiber optic, Wi-Fi, Bluetooth, CANBUS, or USB transceivers.Communication link 530 can be a wired link (e.g. an Ethernet, USB orfiber optic cable) or a wireless link (e.g. a pair of Bluetoothtransceivers). Communication link 530 can transfer laser steeringparameters or equivalent instructions from the processing subassembly520 to the steerable laser assembly 505. Communication link 530 cantransfer ranging data from the steerable laser assembly to theprocessing subassembly 520.

FIG. 6A illustrates exemplary laser steering parameters according toaspects of the technology. A set of laser steering parameters 601 caninclude a start location 602 indicating where one or more other lasersteering parameters should be applied. Start location 602 can be a pointin a Cartesian coordinate system with an associated unit of measure(e.g. 20 mm to the right and 20 mm above the lower right corner of thelower left corner of the FOV). In several laser range finders the FOV isdescribed in terms of angular position relative to an origin in the FOV.For example, a starting point could be +30 degrees in the horizontaldirection and +10 degrees in the vertical direction, thereby indicatinga point in the FOV.

A laser steering parameter can be a region width 604 or a region height606. The width and height of can be expressed in degrees within the FOV.One exemplary set of laser steering parameters could include a startlocation, region width and region height thereby defining a four sidedregion in the FOV. Other laser steering parameters in the exemplary setof laser steering parameters can indicate how to tailor a scan withinthis region, such as laser scan speed 614, laser pulse size 616 (e.g.laser pulse cross sectional area at the exit of a LIDAR), number oflaser pulses 618, or pulse intensity.

A laser steering parameter can be one or more region boundaries 608defining the bounds of a region. For example, region 620 in FIG. 6B canbe defined by the points defining an outer bound 320 and an inner bound330. A steerable laser can be instructed to scan with increased density(e.g. a slower scan speed and a constant pulse rate) within region 620defined by region bounds 608.

A laser steering parameter can be one or more laser pulse locations 610.Pulse locations 610 can provide instructions to a steerable laser tomove to corresponding positions in the FOV and generate one or morelaser pulses. In such embodiments the laser can be generating a laserbeam while being steered from one location to another and can dwell forsome time at the laser pulse locations. In other embodiments thesteerable laser can use these points 610 to generate discrete pulses atthe defined locations. In such embodiments the laser beam can begenerated at discrete pulse locations and can dwell at the pulselocation for some time. In FIG. 6C a plurality of laser pulse locationsform a pattern of pulses 630. A laser steering parameter can be one ormore path waypoints 612, which define points in a FOV where a steerablelaser (e.g. 115 in FIG. 1A) can implement direction changes. FIG. 6Dillustrates two exemplary paths 640 and 650 that can be defined by pathwaypoints (e.g. waypoints 612) and used to instruct steerable laser 110.It would be obvious to a person of skill in the art that several lasersteering parameters can produce equivalent or nearly equivalent regionsof non-uniform pulse density. For example, selecting various combinationof laser steering parameters can cause region 620 in FIG. 6B, pattern ofpulses 630 in FIG. 6C and combination of paths 640 and 650 to producesimilar regions of increased or non-uniform laser pulse density.

FIG. 7 illustrates a process for iteratively refining laser steeringparameters and thereby progressively localizing the boundary of anobject in the field of view. An initial set of laser steering parametersare used to generate laser pulse distribution 702 a. FIG. 7 illustratesan example of iterative boundary localization (IBL), wherein theboundary of an object (e.g. boundary 190 of vehicle 170) is localized toiteratively smaller or more specific subset of the FOV over the courseof several scans of the FOV. A set of reflection data 705 a is gatheredbased on aspects of reflected light measured by a reflection detector(e.g. 450 in FIG. 4) including time-of-flight calculator 455 andintensity calculator 460. In the embodiment of FIG. 7 the set ofreflection data is simplified to be 0 for reflections that are outsidethe boundary of vehicle 170 and 1 for laser pulses with a TOF indicatingplacement within the boundary 220. For the purpose of this disclosure aboundary region can be a region of a field of view encompassing theboundary of an object in the FOV. For example, if laser ranging dataindicates a distinct change in TOF consistent with an object (e.g.vehicle 170) a boundary region 710 a can be calculated that encompassesall locations in which the boundary of the object can be. In this sensethe boundary region can encompass all possible locations of the boundaryof the object in the FOV. Based on the set of reflection data 705 a aboundary region 710 a can be determined, wherein the boundary region canbe selected based on the perimeter of a plurality of points known tocontain boundary 190. The boundary region 705 a can be smaller than theoriginal dense scan region 310 c generated by the laser pulsedistribution. This size reduction of the boundary region relative to thedense scan region can be due to some of the reflection data indicatingthat it is not close to the boundary 190 of vehicle 170, such asreflection data point 703. Boundary region 710 a can be used to generatelaser steering parameters used to instruct a steerable laser to generatelaser pulse distribution 702 b. Dense scan region 310 d formed by asecond set of laser pulses 702 b can have a similar shape to boundaryregion 710 a. The process can be repeated with the second set of laserpulses 702 b yielding a second set of reflection data 705 b. The secondset of reflection data 705 b can indicate a smaller boundary region 710b that can be used to refine laser steering parameters and therebygenerate a third set of laser pulses 702 c. Laser pulse distribution 702c can lie within the perimeter of dense scan region 310 e. After anumber of iterations the boundary 720 of an object (e.g. vehicle 170)can be estimated from the N^(th) set of reflection data (e.g. third setof reflection data 705 c). In the example of FIG. 7 the final boundaryestimate 720 is achieved by selecting a perimeter midway between pointsindicating placement inside the object boundary and points outside theobject boundary. Iterations of refining the laser steering parameterscan be continued until the distance between points outside and insidethe boundary satisfied a distance requirement (e.g. the boundary islocalized to within 50 mm in all locations). In one embodiment the mostrecent set of reflection data can be combined with some or all of one ormore previous sets of reflection data to form a combined set ofreflection data. The set of laser steering parameters can be modified orselected based on the combined set of reflection data. Similarly, thecombined set of reflection data can be processed to determine a modifiedboundary region that functions to identify a region that contains aboundary of an object. The modified boundary region can then be used togenerate or refine laser steering parameters that dynamically steer alaser beam (e.g. configure a steerable laser) to generate a dense scanregion with the shape and location of the modified boundary region.

FIG. 8 illustrates application of a common boundary estimation criterionto the initial data set 705 a and the third set of data 705 c, therebyyielding boundary estimates 810 and 720 respectively. It can beappreciated that iteratively refining the laser steering parametersgenerates a boundary estimate 720 that is an improvement over theinitial result 810.

FIG. 9 illustrates a functional diagram wherein sensor data from a oneor more of a variety of sources can be used to generate laser steeringparameters for a steerable laser. A uniform laser scan pattern in a FOV130 can be augmented, refined or replaced by one or more sets of lasersteering parameters based on sensor data from or regarding the localenvironment. Examples can include event-driven laser steering parameterselection such as processing image data from a camera 910 a, detecting aperson with classifier 490 and thereby generating laser steeringparameters 601 c. Laser steering parameters 601 c include a scan path950 adapted to the shape of a person and can be applied in a portion ofor location within the FOV 130 indicated by first data. Laser steeringparameters can also be based on the probability of events. For example,GPS sensor data from a GPS receiver 910 can indicate that the laserrange finding system (e.g. 110 in FIG. 1B) is in an urban environment.The system (e.g. 110 in FIG. 1B) can be programmed store and implement aparticular set of laser steering parameters (e.g. urban laser steeringparameters 601 d) operable to dynamically steer a laser to account foran increased probability of urban hazards such as pedestrians,cross-traffic, and obstructed or narrow streets. Similarly, sensor dataprocessor 475 can receive weather data from weather sensors (e.g. rainsensors or temperature sensors) or light-level sensors. Sensor dataprocess 475 or classifier 490 can process the weather data and instructlaser steering parameter generator 410 to generate a set of lasersteering parameters such as day/night parameters 601 e based on theweather data. For example, in wet conditions laser pulses can beconcentrated in a region of the FOV designed to detect obstacles furtheraway to account for increase stopping distance.

In general a wide variety of sensor data can be gathered form a varietyof sources such as camera 910 a, inter-vehicle transceiver 910 b, GPSreceiver 910 c, RADARS 910 d, LIDAR 910 e, passive infrared sensor (PIR)910 f, sound sensor 910 g and weather/environmental sensor 910 h. Thissensor data can be processed by a data processor 475, classified by aclassifier 490 and supplied to a laser steering parameter generator 410.Laser steering parameter generator/modifier 410 can generate a many setsof laser steering parameters based on sensor data, such as set 601 acontaining a predefined patterns of laser pulse points (e.g. pattern920) corresponding to classification indicating a passenger vehicle sideview. Another exemplary set of laser steering parameters 601 b candefine a region 940 corresponding to a classification or sensor dataindicating the rear of a vehicle. Region 940 can be scanned with a densepattern of laser pulses in order to determine whether characteristicfeatures associated with the rear of a vehicle are present.

Operation

FIG. 10A is flow diagram of a process 1000 of selecting laser steeringparameters based on sensor data and dynamically steering a laser basedon the laser steering parameters, according to an embodiment of thepresent disclosure.

At block 1010 method 1000 starts. At block 1020, sensor data indicativeof one or more aspects of a local environment of a laser range finderhaving a laser is obtained. At block 1030, a set of laser steeringparameters, based on the sensor data is obtained. At block 1040, thelaser is dynamically steered according to the set of laser steeringparameters, to generate a set of laser pulses in a sequence ofdirections in a field of view. At block 1050, the laser range findermeasures one or more aspects of a reflected light from the set of laserpulses, thereby generating reflection data. At block 1060 method 1000stops.

FIG. 10B is flow diagram of a process 1001 of selecting laser steeringparameters based on data and dynamically steering a laser based on thelaser steering parameters, according to an embodiment of the presentdisclosure. At block 1015 a laser range finder having one or moresteerable lasers, generates a first set of laser pulses at a first setof directions in a field of view. At block 1025 the laser range findermeasures one or more aspect of reflected light from the first set oflaser pulses and thereby generating first data. At block 1035, the laserrange finder generates a set of laser steering parameters based at leastin part on the first data. At block 1045 the laser range finderdynamically steers at least one of the one or more steerable lasers,based on the set of laser steering parameters, thereby generating one ormore second laser pulses at one or more second locations in the field ofview. At block 1055, the laser range finder measures one or more aspectsof reflected light from the one or more second laser pulses to generatesecond data. In one example, sensor data from the local environment canbe inter-vehicle communication data from a first vehicle that causes aLIDAR in a second vehicle to obtain or generate a set of laser steeringparameters and dynamically steer or configure a laser in a LIDAR tonon-uniformly scan a FOV.

In a related second group of embodiments a method to complete adynamically steered non-uniform LIDAR scan of a FOV within a target timeis disclosed. A time target to complete a LIDAR scan of a FOV can becombined with sensor data from the local environment to generate lasersteering parameters operable to configure a LIDAR to dynamically steer.Laser steering parameters (e.g. laser instructions) can be selectedbased on information from the local environment as well as based atleast in part on a time target to complete the scan. In this way thedensity of laser ranging measurements can be tailored to ensure that thewhole FOV or a defined portion of the FOV is scanned within the targettime. During a first scan of the FOV a region of the FOV can beidentified. During a second scan of the FOV the identified region canreceive a dense scan with a smaller point spacing than the average laserpulse spacing. The shape of the regions and the scan point density canbe selected based on requirements to complete the scan in a reasonabletime.

Laser steering parameters (e.g. laser instructions) can be selectedbased on information from the local environment as well as based atleast in part on a time target to complete the scan. In this way lasersteering parameters can configure a LIDAR to both dynamically steer alaser to generate a sequence of laser pulses (e.g. based on aclassification, discovered boundary or location of an object), andensure that the scan is completed within a target time or a targetnumber of laser pulses. During a first scan of the FOV a region of theFOV can be identified. Laser steering parameters can be generated basedat least in part on a target time and based in part on the identifiedregion. During a second scan a laser can be dynamically steeredaccording to the laser steering parameters to perform a dense scan withsmaller point spacing than the average laser pulse spacing.

In a related embodiment, first data received by a processing subassemblyof a laser range finder (e.g. 520 in FIG. 5) can identify one or moreregions of a FOV containing objects of interest (e.g. vehicles, cyclistsor pedestrians). The processing subassembly can configure a steerablelaser assembly based on a target time to complete a non-uniform laserranging scan of the FOV. In some cases the first data can identify densescan regions and the target time can be used to generate laser steeringparameters for the dense scan regions that control laser pulse density(pulses per angular range), scan velocity, dwell time in each region.

In one example a laser range finding system (e.g. a LIDAR) identifies atime of flight boundary (e.g. an object edge) based on laserreflections, and generates a set of laser steering parameters toinvestigate the boundary using a complex laser trajectory. The targettime can be used to generate a laser steering parameter that is acriteria for when the laser should cease to localize the boundary withadditional dynamically steered laser pulses. For example, in order tocomplete a laser ranging scan in 100 milliseconds a laser range findersystem can generate a laser steering parameter that dictates that aboundary is sufficiently localized if it lies in a 0.5 degree azimuthalangular range. The laser steering parameter can be based on the targettime if it is calculated, selected or configured based on the value orexistence of a target time.

In one embodiment a method performed by a laser range finding systemcomprises: First, obtaining first data indicative of one or more aspectsof an environment local to the laser range finder comprising a laser,secondly obtaining a time target for completion a laser ranging scan.Thirdly the method obtains a set of laser steering parameters based onthe first data and based at least in part on the time target. Fourthlythe method performs a scan of a field of view by dynamically steers thelaser according to the set of laser steering parameters, to generate aset of laser pulses in a sequence of directions. Fifthly the methodmeasures one or more aspects of reflected light from the set of laserpulses, thereby generating reflection data. Finally the method completesthe laser ranging scan within the target time.

FIG. 10C is flow diagram of a method 1002 for selecting laser steeringparameters based on sensor data and a time target to complete a scan anddynamically steering a laser based on the laser steering parameters,according to an embodiment of the present disclosure.

At block 1020, sensor data indicative of one or more aspects of a localenvironment of a laser range finder having a laser is obtained. Thesensor data can be obtained in wireless signals (e.g. from othervehicle), obtained from sensors on the same vehicle as the laser rangefinder, obtained by the laser range finder, or obtained from a memorycontaining sensor data. At block 1023 a time target for a scan of atleast a portion of a field of view is obtained. The time target can be atotal time for the scan of the whole FOV (e.g. 100 ms). At block 1033 aset of laser steering parameters is obtained, based on the sensor dataand the target time. The set of laser steering parameters can beobtained by calculation, selection or memory access. For example, inresponse to identifying person 160 and vehicle 170 in FIGS. 1A and 1 nresponse to obtaining a time target that a scan of the FOV should take0.1 seconds a laser range finder can determine a laser pulse density anda trajectory that scans two dense scan regions surrounding person 160and vehicle 170 in FIG. 1B. In one example sensor data indicatingobjects of interest in the FOV can be used to generate laser steeringparameters to define the size of dense scan regions. The time target canfurthermore be used to generate a laser steering parameter defining anangular velocity (and hence laser pulse dense) within the dense scanregions.

At block 1043, the laser is dynamically steered according to the set oflaser steering parameters, to generate a set of laser pulses in asequence of directions that scan the field of view within a target time.At block 1050 one or more aspects of a reflected light from the set oflaser pulses are measured to generate reflection data.

In a related third group of embodiment a method to dynamically configurea LIDAR by identifying objects or regions of interest in a FOV anddynamically apportioning LIDAR resources (e.g. number or density oflaser pulses), based on number of relative importance of identifiedobjects is disclosed. In one embodiment a laser range finding systemobtains sensor data from an environment local to the LIDAR and therebyidentifies a plurality of objects. The laser range finding system thenassigns one or more weights to each of the plurality of objects, whereinthe weights function to non-uniformly apportion laser range measurementsin the FOV of the LIDAR. The laser range finding system uses the weightsto generate laser steering parameters (e.g. instructions to configure adynamically steerable laser in the LIDAR) and dynamically steers asteerable laser in the LIDAR according to the laser steering parameters.The method can thereby dynamically steer a LIDAR to generate anon-uniform density pattern of laser ranging measurements based on thenumber of relative importance of discovered objects.

In one example, a LIDAR with a dynamically steerable laser may gathersensor data from a FOV that indicates one important object and no otherobjects of any importance. Laser steering parameters can be generated tosteer the laser in a region surrounding the object with a density of onelaser pulse for each 0.2 degrees of horizontal sweep in the FOV and adensity of one pulse per degree of horizontal sweep outside the regioncontaining the object. If at a later time three objects of equalimportance (e.g. weighting) are detected in the FOV, the laser steeringparameters can be modified to generate one pulse per 0.5 degrees ofhorizontal sweep in the regions surrounding each of the three objects.Hence embodiments of this disclosure can apportion laser pulses based onassigned priority or weight of objects. Weights can be relativeweightings, wherein the weight assigned to a first object is based atleast in part on the weight assigned to a second object. For example,weights can be normalized by initially assigning a weight to each objectform a plurality of objects and later dividing each object weighting bythe combined weights for each of the plurality of objects. Objects thatexhibit interesting or changing behavior (e.g. movement, appearing inFOV, or an interesting classification) can be assigned increased weightsand hence an increased density of laser ranging measurements based onthe set of laser steering parameters. The weight assigned to each of aplurality of objects or regions in a FOV can be used to generate a setof laser steering parameters with individually tailored density, densescan region shapes, laser beam trajectories, intensities, spot sizes orperiodicity with which the region or object is revisited by a steerablelaser in a LIDAR.

FIG. 10D is flow diagram of a method 1003 for selecting laser steeringparameters based on one or more weights applied to identified objectsand dynamically steering a laser based on the laser steering parameters,according to an embodiment of the present disclosure.

At block 1020, sensor data indicative of one or more aspects of a localenvironment of a laser range finder having a laser is obtained. Thesensor data can be received in wireless signals, sensed by the laserrange finder, sensed by other sensors on a common vehicle or looked upbased on a location of the vehicle from a database of sensor data.

At block 1024, the sensor data is processed to identify a plurality ofobjects in the local environment. At block 1026, one or more weights areassigned to each of the plurality of identified objects. The weightassignment can be based on processing the sensor data to identifymovement, object classification, object trajectory. The weightassignment can be based on a lookup operation (such as assigning aweight of 5 to all objects with ranges <10 meters from a laser rangefinder). In another example a first object, can be identified as a car,sensor data can be vehicle-to-vehicle (V-V) communication signals andupon processing the V-V communication signals the object (i.e. the car)can receive a weight of 10. Another object (e.g. a pedestrian) canreceive a weight of 15 based on normalized weighting relative to thecar, based on the contents of the V-V communication signals indicatingthe presence of the pedestrian, based on a recent arrival of thepedestrian in the FOV or based on a trajectory of the pedestrian (e.g.into the path of laser range finder conducting method 1003).

At block 1028, a set of laser steering parameters is obtained, based onat least in part on a first weight corresponding to a first object fromthe plurality of objects. In several embodiments the laser steeringparameters can be calculated by processing the weights corresponding tothe plurality of identified objects. For example, the weights can beprocessed to normalize, prioritize or rank the weights to identifyparticular corresponding objects in need of increased laser pulsedensity. At block 1040, the laser is dynamically steered according tothe set of laser steering parameters, to generate a set of laser pulsesin a sequence of directions in a field of view. At block 1050, the laserrange finder measures one or more aspects of a reflected light from theset of laser pulses are to generate reflection data. At block 1060method 1003 stops.

FIG. 11 illustrates a flow diagram of a process 1100 of refining a setof laser steering parameters based on measured data, according to anembodiment of the present disclosure. At block 1110 method 1100 begins.At block 1120 a set of laser steering parameters for at least one laserin a set of steerable lasers is obtained. At block 1130 at least onelaser in the set of steerable lasers is dynamically steered, based onthe set of laser steering parameters, thereby generating one or morefirst laser pulses at one or more first locations in the field of view.At block 1140 one or more aspects of reflected light from the one ormore first laser pulses is measured, thereby generating first data. Atblock 1150 method 1100 assesses if features in first data aresufficiently localized. If it is determined that features in first datasuch as boundaries or edges are sufficiently localized method 1100 stopsat step 1170. Otherwise method 1100 proceeds to block 1160 where the setof laser steering parameters based on the first data are refined,wherein the refinement can increase the laser pulse density in regionsencompassing features.

FIG. 12A illustrates a flow diagram of computer implemented method 1200of selecting a set of laser steering parameters based on classificationof an object in the local environment, according to an embodiment of thepresent disclosure. At block 1205 an object classification based onsensor data from the local environment is generated. At block 1210 a setof laser steering parameters based on the object classification isobtained. For example, if an object in the local environment isclassified as a vehicle a set laser steering parameters can becalculated or retrieved from memory. At block 1215 method 1200 instructsa steerable laser assembly to steer based on the laser steeringparameters and thereby generate a first set of laser pulses at a firstset of locations in the field of view. At block 1227, first dataindicating one or more aspects of reflected light from the first set oflaser pulses laser is measured.

FIG. 12B illustrates a flow diagram of a method for steering a laserrange finder according to an object classification and performing aclassification test on the resulting range data to determine whether thelaser reflection data (and the object) satisfy the object classificationtest. At block 1204, an object classification is obtained for an objectin a field of view of a laser range finder, having a steerable laserassembly. The object classification is based on sensor data from a localenvironment of the laser range finder. At block 1210, a set of lasersteering parameters are obtained based on the object classification. Atblock 1215 method 1200 instructs a steerable laser assembly to steerbased on the laser steering parameters and thereby generating a firstset of laser pulses at a first set of locations in the field of view. Atblock 1220, first data indicating one or more aspects of reflected lightfrom the first set of laser pulses laser is obtained. At block 1225 aclassification test is obtained and applied to the first data. Theclassification test can have test vectors for characteristics of theobject classification (e.g. characteristics of a car, a person, or abuilding).

At block 1230 the classification test is assessed on the first data. Ifthe first data satisfies the classification test method 1200 stops at1235. Otherwise method 1201 returns to block 1204 and generates anotherclassification. Method 1201 can be performed multiple times withincreasingly detailed classification tests to identify ever moredetailed types and models of objects (e.g. classifications of vehicles).

Progressive Boundary Localization

FIGS. 13, 14A, 14B, 15 and 16 illustrate several embodiments of aprogressive boundary localization (PBL) method. The PBL method candynamically steer a laser range finder based in part on range dataindicating regions with time-of-flight differences (e.g. indicatingobject boundaries) and thereby enhance the accuracy of the boundarylocations by dynamically steering a laser to produce additional laserpulses within the regions.

In a first PBL embodiment a method for performing a laser scan of arange of orientations while localizing time of flight (TOF) boundariescan comprise the steps of: steering a LIDAR device in the range oforientations while emitting a sequence of laser pulses, receiving withthe LIDAR device a set of reflections corresponding to the sequence oflaser pulses and measuring for each of the sequence of laser pulses acorresponding TOF and a corresponding direction. The method furthercomprises the step of at one or more times during the laser scan, inresponse to identifying a pair of laser pulses that are nearestneighbors and for which the corresponding TOFs have a difference greaterthan a TOF threshold, steering the LIDAR device to generate a new laserpulse in the sequence of laser pulses with a new direction based on thedirection of at least one laser pulse in the pair of laser pulses andsuch that upon generation the pair of pulses cease to be nearestneighbors. The method can further comprise the step of completing thelaser ranging scan such that upon completion of the laser ranging scanall pairs of laser pulses in the sequence of laser pulses that arenearest neighbors for which the corresponding TOFs have a differencegreater than the TOF threshold have a difference in directions less thansome minimum separation.

Turning to FIG. 13 in one embodiment of a PBL method a laser rangefinder 110 can comprise one or more a dynamically steerable lasers (e.g.laser 121) that can scan a FOV 1310 comprising an azimuthal angularrange 1315 and an elevation angular range 1320. The dynamicallysteerable laser 121 can receive and process a plurality of lasersteering parameters to sweep a laser beam through a plurality oforientations, illustrated by path 1325 in FOV 1310. While sweep path1325 steerable laser 121 can generate a sequence or set of laser pulseseach with a corresponding direction illustrated by “+” symbols in FIG.13. Some of the laser pulses (e.g. pulse 1330) can intersect withobjects (e.g. vehicle 170, indicated by boundary 190). Other pulses(e.g. pulse 1335) may not intersect with the vehicle.

Turning to FIG. 14A, the laser range finder can receive a set of laserreflections corresponding to the sequence of laser pulses and canmeasure for each laser pulse in the sequence of laser pulses acorresponding direction and a corresponding time of flight (e.g. 100 nS)or range (e.g. 30 m). The set of TOFs and set of directionscorresponding to the sequence of laser pulses is illustrated as datamatrix 1405. Data matrix 1405 can also be stored as a list of directionsand corresponding TOFs for each laser pulse in the sequence of laserpulses. For the purpose of illustration laser reflections from vehicle170 have a TOF of 3 and laser reflections from outside the boundary 190of vehicle 170 have a TOF of 9. A challenge is to identify the locationof boundary 190 from data matrix 1405. One approach is to identifynearest neighbors for each laser reflection and to identify if a TOFboundary lies between the nearest neighbor pairs. Each laser pulse (e.g.the laser pulse illustrated by data point 1410) can have a plurality ofnearest neighbors in a plurality of directions or a plurality of rangesof directions (e.g. direction 1415 and 1420).

Turning to FIG. 14B several pairs of laser pulses (e.g. pairs 1424 a-c)can be identified such that the difference in the TOF between laserpulses in each pair is greater than a threshold value. For example, pair1425 a contains a first laser pulse within the vehicle perimeter with aTOF of 3 and a second laser pulse outside the vehicle perimeter with aTOF of 9. The difference in the TOF values can be greater than a TOFthreshold of 5, thereby indicating the presence of a TOF boundary (e.g.the edge of a vehicle) in the angular range between the directionsassociated with each of the laser pulses in each pair.

FIG. 15 illustrates the original FOV 1310 and the original sequence oflaser pulses. In response to identifying the pairs for which the TOFdifference is greater than a threshold value (e.g. pairs 1425 a-c inFIG. 14B), one or more second laser steering parameters can bedynamically generated to steer the steerable laser along a path 1520that generates additional laser pulses in the intervening spacescorresponding to each of the pairs. For example, laser pulses 1510 a-bcan be generated as the steerable laser moves along path 1520. Path 1520can be a complex shape (e.g. roughly outlining the boundary 190 ofvehicle 170). In one aspect, the second set of laser steering parametersto generate path 1520 can vary two angular velocities simultaneouslybetween neighboring laser pulses 1510 d and 1510 e. In another aspect,path 1520 can cause the steerable laser to change direction from anegative azimuthal angular velocity before laser pulse 1510 c to apositive azimuthal angular velocity after laser pulse 1510 c. The PBLmethod enables the intervening laser pulses 1510 a-e to be located inparts of the FOV 1310 estimated to contain an object boundary (i.e. thathave TOF differences greater than the TOF threshold.

The direction of each of the intervening pulses 1510 a-e is indicated bythe 2-D location in the FOV 1310. The direction of intervening pulse1510 a can be based one or more of the directions of the correspondingpair of laser pulses 1425 a. For example, path 1520 can be designed toplace pulse 1510 a midway between the laser pulses in pair 1425 a. Path1520 can place intervening pulses 1510 a-e at specified angulardirection relative to one of the pulses in each of the pairs of laserpulses with TOF difference. For example, the first sequence of laserpulses produced by steering the LIDAR 110 along path 1325 in FIG. 13 canhave an angular spacing of 1 degree in elevation and 1 degree azimuthal.Intervening laser pulses 1510 a-e can placed in a direction in the FOV1310 with a separation of 0.3-0.5 degrees from one of the laser pulsedirections in the corresponding pairs of laser pulses. The interveninglaser pulses 1510 a-e can be located a defined angular separation from afirst pulse in a corresponding laser pulse pair and in a directiontowards the second laser pulse in the pair, thereby ensuring that eachintervening laser pulse destroys the nearest neighbor relationship ofthe corresponding laser pulse pair (e.g. 1425 a in FIG. 14B). In thisway nearest neighbor pairs 1425 a-c with a TOF difference greater than aTOF threshold may no longer be nearest neighbor pairs when theintervening laser pulses are generated.

Intervening laser pulses (e.g. pulses 1510 a-b) can be added to thesequence of laser pulses. In one aspect intervening laser pulse 1510 acauses laser pulse pair 1425 a in FIG. 14B to no longer be a nearestneighbor pair. Therefore, as intervening laser pulses are added to thesequence of laser pulses the nearest neighbor pairs can be modified bynew intermediate laser pulses.

Turning to FIG. 16 the laser range finding system can calculate a TOF1610 a-h for each of the intervening laser pulses. FIG. 17A-Eillustrates an embodiment of a PBL method wherein a LIDAR scans a FOVand generates a sequence of range measurements that progressivelylocalize time-of-flight boundaries. In the embodiment of FIG. 17A-Enearest neighbor pairs of laser pulses are identified in a sequence oflaser pulses, such that the TOF difference between pulses in eachnearest neighbor pair is greater than a TOF threshold and theniteratively adding intervening laser pulses with directions that destroythe nearest neighbor relationship of the corresponding laser pulsepairs. The LIDAR can dynamically steer and generate intervening laserpulses, thereby refining the location of the TOF boundary, until eachnearest neighbor pair with a TOF difference greater than the TOFthreshold are separated by less than a threshold distance (e.g. adirection difference less than 0.5 degrees).

In FIG. 17A a laser range finding system can scan a 2-D (elevation,azimuthal) range of orientations while generating a sequence of laserpulses 1705. In FIG. 17B the laser range finder system can receive asequence of laser reflections 1707 corresponding to the sequence oflaser pulses 1705 and can measure or calculate a direction and TOFcorresponding to each of the outgoing sequence of laser pulses. Thelaser range finder system can identify one or more of the sequence oflaser pulses (e.g. pulse 1709 in FIG. 17A) for which the difference inTOF to a nearest neighbor pulse is greater than a threshold value. Forexample, the TOF difference between laser pulse 1708, within the vehicle170 and nearest neighbor pulses 1709 a-c outside the vehicle perimetercan be greater than a threshold (e.g. a TOF threshold of 5). FIG. 17Billustrates three pairs 1710 a-c of laser reflections for which the TOFdifference (i.e. the difference between a first TOF in the pair and asecond TOF from the pair) is greater than a threshold.

In FIG. 17C the laser range finder system can generate a set of lasersteering parameters and use these to guide the system along a path 1712to generate intervening laser pulses e.g. 1715. The intervening laserpulses and path 1712 can have directions in the FOV based on one or moreof the laser pulses in the pairs of laser pulses 1710 a-c. In FIG. 17Dtime of flight data can be measured for the intervening laser pulses andthey can be added to the sequence of laser pulses 1705. A TOF test canagain be performed that identifies those nearest neighbor pairs of laserpulses for which the TOF difference is greater than a TOF threshold. TheTOF threshold can be modified each time the TOF test is performed inorder to localize iteratively smaller TOF differences. In FIG. 17D threenew pairs of laser pulses 1720 a-c are generated that fail the TOF test(i.e. have TOF differences greater than a TOF threshold). In one aspectof several embodiments the location of the intervening pulses can beseen to prevent the original laser pulse pairs 1710 a-c from reoccurringduring subsequent applications of the TOF test, thereby ensuring thatthe boundary (e.g. boundary 190 in FIG. 17A) is localized to a smallerarea in successive iterations of the TOF test. In FIG. 17E the laserrange finder system uses the identified pairs of laser pulses togenerate a new path 1725 with more intervening laser pulses (e.g. 1727).FIG. 17F illustrates that the TOF test can be applied again to identifypairs of nearest neighbor laser pulses (1730 a-c) between which the TOFboundary 190 lies. The TOF test can be applied until each pair ofnearest neighbor pulses that fails the TOF test has an angularseparation e.g. 1740 less than a threshold separation or distance (e.g.an angular separation between points in each pair of less than 0.5degrees).

In several embodiments, a LIDAR can apply a boundary localization testto each point in an existing set of laser pulses with correspondingdirections and TOF values. The localization test can define severalangular ranges. Consider that laser reflection 1410 in FIG. 14A can belocated at 0 degrees elevation and 0 degrees azimuth. An angular rangecan be all negative elevation angles along direction 1415. An exemplary2-D angular range relative to point 1410 can be elevation angles with arange 0-1 degree and azimuthal angles in a range 0-1 degree, therebydefining a box 1417. The localization test can identify for each laserpulse whether there exists a nearest neighbor for each of the angularranges for which the TOF difference is greater than a TOF threshold andfor which the angular separation (e.g. the square root of the sum of thesquares of the angular separations along each of the elevation andazimuthal axes) is greater than a threshold separation. When such anearest neighbor exists the laser pulses in the sequence fails thelocalization test and the PBL method places an intervening laser pulsesin the region between the laser pulses and the nearest neighbor and addsthe intervening laser pulse to the sequence thereby destroying thenearest neighbor relationship between the laser pulses and the originalnearest neighbor. In one aspect a PBL method, immediately aftergenerating an intervening laser pulse a LIDAR can apply the localizationtest to the new intervening laser pulse. In this way a LIDAR caniteratively localize a TOF boundary, such that all pairs of laser pulsesbetween which the TOF boundary lie are separated by no more than athreshold angular separation.

FIG. 18 illustrates a PBL method wherein a LIDAR identifies a firstportion of a TOF boundary in a FOV and estimates a direction (i.e. anangular offset in the FOV) to reach a search zone (e.g. an angularrange) wherein the LIDAR searches for a second portion of the TOFboundary.

Several embodiments of FIG. 18 can be considered extrapolation-basedprogressive boundary localization (EPBL) methods. Using EPBL one or morelocations on a TOF boundary identified by a LIDAR in a first searchregion within a FOV can be used to extrapolate or predict an estimatedboundary location outside of the first search region. The LIDAR can thendynamically steer to generate a second search region based on theestimated boundary location. The extrapolation of the estimated boundarylocation can be based on the shape of a line through the one or morelocations identified on the boundary (e.g. a straight line fit throughtwo locations or a curve fitted through 3 or more locations). In otherembodiments the extrapolation of a predicted or estimate boundarylocation outside the first search region can be based on aclassification of the type of boundary. For example, many objects that aLIDAR on an autonomous vehicle can encounter have common shapecharacteristics within various object classifications such as commonroad intersection patterns, trucks shapes, overpasses, pedestrians,cyclists or buildings. An extrapolation of an estimated boundarylocation can be based on processing one or more known boundary locationsin the context of one or more predicted object classifications. Forexample, a newly discovered TOF boundary may be one or many object types(e.g. a tree or a pedestrian at the corner of a road intersection). Anexemplary EPBL embodiment could apply a 50% probability that theboundary is the trunk of a tree and a 50% probability that the boundaryis the body of a person and estimate a boundary location outside a firstsearch region based on the blended classification and the one or moreknown boundary locations. Subsequent search regions generated based onthe estimated boundary location can cause the predicted classificationto favor either the tree or the person and future extrapolation ofestimated boundary locations can be weighted according to the set ofknown boundary locations and the updated classification weightings.

Various embodiments provide for calculating a confidence value orstandard deviation associated with the direction (i.e. the angularoffset to reach a new search zone defined by an estimated boundarylocation or vector). For example, everyday objects can have boundariesor edges with simple shapes (straight lines or simple curves) arrangedin a direction relative to an observation point. Hence while it may beimpractical for a rotating LIDAR to try to dynamically track and scanthe boundary of object at an arbitrary orientation, it may be morepractical to use a dynamically steerable LIDAR. In comparison to asteerable RADAR that tracks an objects movement from one scan to anotherand can predict a direction for the object, the disclosed PBL method canestimate the edges of an object within a single scan by finding a firstportion of an edge and predict a direction for the edge (based on curvefitting, object classification or extrapolation). The method can thenscan a laser beam in a pattern at a second location some distance alongthe predicted direction of the boundary in the FOV. Turning to FIG. 18 aLIDAR 1805 can scan a dynamically steerable laser 1806 in a first 2-Dangular range 1815 (e.g. defined by an elevation angular range 1830 anda azimuthal angular range 1825). The total FOV of LIDAR 1805 can includeseveral boundaries such as road edges 1810, 1811 and 1812. LIDAR 1805can scan a path that comprises a sequence of orientations in the 2-Dangular range. While scanning the path LIDAR 1805 can generate asequence of laser pulses and measure a corresponding sequence of laserreflections. LIDAR 1805 can calculate a TOF (e.g. TOF 1820) or adistance corresponding with each of the sequence of outgoing laserpulses. The TOF values can have differences that indicate approximatelocation of a first portion of boundary 1810. For example, the TOFvalues (e.g. TOF 1820) can indicate angular regions 1835 a-b thatencompass a part of the boundary 1810. In one embodiment the LIDAR 1805can calculate one or more regions in angular range 1815 that intersectsthe boundary. In other embodiments LIDAR 1805 can calculate one or morelocation estimates for points on the boundary 1810. For example, the PBLmethod can estimate that points on boundary 1810 are located midwaybetween nearest neighbor points that indicate they are on opposite sidesto the TOF boundary based on a TOF difference. One or more firstlocations or regions on the boundary 1810 can be used by the LIDAR tocalculate a vector 1840 or 1841 used to steer the LIDAR 1805 to a secondregion estimated to overlap a second portion of boundary 1810. Shiftvector 1840 can be a 2-D direction shift (e.g. a 10 degree elevationangle shift and a −10 degree azimuthal angle shift) to change theorientation of steerable laser 1806 from the first angular range 1815 toa second angular range 1846. In one aspect a shift vector 1841 can pointto a search region 1847 that does not span the boundary 1810. In thiscase, in response to identifying that a search region (e.g. region 1847including laser pulse 1850) does not contain a boundary, a new largersearch region 1855 can be defined in an effort to reacquire the boundary1810. One advantage of the EPBL method of FIG. 18 is that a secondsearch region need not surround or adjoin a first search region. Insteada first search region can identify a direction of a TOF boundary. Thedirection can be used to generate a vector 1840 (i.e. a 1-D or 2-Dangular shift) that functions to shift LIDAR 1805 to a new searchlocation. In a related embodiment several locations on a first portionof a boundary calculated from a first search area can be used tointerpolate a shape and direction of a boundary (e.g. a line or acurve). For example, three locations identified on a boundary 1810 froma first sequence of laser pulses including laser pulse 1820 can be usedto define a curve or an arc 1857 on which other portions of the boundary1810 are expected to lie.

In a related embodiment, a LIDAR can scan a path including a sequence oforientations in a first 2-D search region 1860 of a FOV. While scanningthe path, the LIDAR can generate a plurality of laser pulses, receive acorresponding sequence of laser reflections and calculate a TOFcorresponding to each of the outgoing laser pulses. The LIDAR canidentify the presence of a TOF boundary (e.g. the edge of a vehicle orthe edge 1811 of a roadway), by identifying one or more nearest neighborpairs of laser reflections for which the TOF difference is greater thana TOF threshold. The LIDAR can calculate a set of boundary locations(e.g. locations 1862 a and 1862 b) based on the TOF measurements fromthe first search region 1860. The LIDAR can process one or morelocations in the set of boundary locations (e.g. locations 1862 a and1862 b) to predict an estimated boundary location 1863 a, locatedoutside the first search region. The LIDAR can generate a set of lasersteering parameters, based on the estimated boundary location anddynamically steer a laser 1806 based on the laser steering parameters togenerate a second plurality of laser pulses (e.g. including laser pulse1870) in a second search region. In this way a LIDAR scan can be guidedby identifying and adding directions in a FOV (e.g. locations in a FOV)that lie on a TOF boundary, predicting and estimated boundary locationoutside a first search region and scanning a second search regions withlaser pulses based on the predicted trajectory of the TOF boundary. Themethod can be performed iteratively in the course of a single scan bybuilding up a set of confirmed boundary locations, predicting estimatedboundary locations and scanning a second search region around theestimated boundary location. In one embodiment of an EPBL methodillustrate in FIG. 18, a first search region 1860 is used to generateboundary locations 1862 a-b, that are then used to extrapolate theestimate boundary location 1863 a or vector 1865 a pointing to a secondsearch region. A LIDAR scans a second search region to identify anotherboundary location 1862 c that is added to the set of boundary locations.The updated set of boundary locations can be used to extrapolate a newestimated boundary location 1863 b or an associated vector 1865 bleading to a third search region that can be defined by path 1864. Path1864 can have a complex shape involving a number of right angle turns ordirection reversals with the FOV, thereby requiring dynamic steering ofthe LIDAR. In FIG. 18 the third search region (e.g. defined by path1864) does not intersect or contain the TOF boundary 1811. For example,all laser pulses along path 1864 can have reflections that indicate acommon TOF associated with one or other side of boundary 1811. In oneaspect, in response to identifying that a search region does not containa boundary location (i.e. does not intersect a TOF boundary) an EPBLmethod can generate a new estimated boundary location 1863 c anddynamically steer a laser 1806 to generate a new search region 1872. Thenew search region 1872 can have a wider angular range designed toreacquire the boundary location surrounding the new estimated boundarylocation 1863 c. The new estimated boundary location 1863 c can be basedon one, some or all of the locations in the set of boundary locations aswell as the estimated boundary location 1863 b that failed to generate anew boundary location. Search region 1872 can yield reflections thatindicate a divergence or splitting of a TOF boundary. Such TOF boundarysplitting can occur where objects overlap in the FOV of the LIDAR 1805.Consider that many common objects that a vehicle-based LIDAR mayencounter can comprise a series of intersecting straight-line or curvedboundaries, such as the intersecting architectural lines of an overpassor a freeway exit. In response to identifying two intersecting ordiverging boundaries in a search region 1872 (e.g. indicated by boundarylocations 1862 d and 1862 e), the LIDAR can generate distinct estimatedboundary locations 1863 d and 1863 e (or vectors 1865 d and 1865 e) formultiple distinct TOF boundaries 1811 and 1812.

In another embodiment of a EPBL method a LIDAR 1805 can track severalTOF boundaries 1810 and 1811 simultaneously, by several distinct sets ofboundary locations and periodically generating a new search regions foreach based on a new extrapolated estimated boundary location. An EPBLmethod that tracks several boundaries at once can perform differentfunctions in parallel such as extrapolating an estimated boundarylocation for a first boundary while scanning a new search region for asecond boundary. Similarly an EPBL method can perform a wide angle 2-Dscan of a FOV to search for new TOF boundaries while extrapolatingboundary locations and tracking one or more previously discoveredboundaries.

FIG. 19 illustrated an embodiment wherein an angular range 1930 isassociated with a vector 1925 extrapolated from a set of boundarylocations 1911 a and 1911 b. This angular range or confidence value canbe based on how well the boundary locations fit a particular shape. Forexample, the angular range or confidence value can be based on the meansquare error of line or curve fit to the set of boundary location usedto generate vector 1925 or estimated boundary location 1912 a.

Turning in detail to FIG. 19 a LIDAR 1805 can have a FOV 1905 comprisinga 2-D angular range comprising a range of possible elevation angles 1906and a range of possible azimuthal angles 1907. An EPBL method performedby a LIDAR can scan a first search region comprising an elevationangular range 1910 and an azimuthal angular range 1911, to produce afirst set of laser pulses. The LIDAR can measure a set of reflection1915 corresponding to the outgoing sequence of laser pulses and canmeasure a TOF (e.g. 1920) corresponding with each laser pulse in thesequence. The LIDAR can calculate a set of locations (e.g. location 1911a and 1911 b) on a TOF boundary 1908 and can further extrapolate avector 1925 (and confidence range 1930) to an estimated boundarylocation 1912 a. The LIDAR can dynamically steer a laser 1806 togenerate a second set of laser pulses 1935 based on the vector 1925 orthe estimated boundary location 1912 a. The size of the second set oflaser pulses 1935 can be based on the confidence value 1930. Forexample, if processing the set of boundary locations indicates astraight-line boundary with a small mean square error line fit, theangular range or confidence value associated with vector 1930 can besmall and consequently the size of the second set of laser pulses 1935can be small. Conversely, if the set of boundary locations indicate aboundary with a complex shape (e.g. a tree) the angular range 1930 canremain high, or the confidence value associated with estimated boundarylocation 1912 a can remain low, thereby causing laser 1805 todynamically scan a larger search region 1935. Over time as the set ofboundary locations grows to include 1911 c and 1911 d the angular range1945 associated with subsequent vectors 1940 indicating the location ofsubsequent estimated boundary locations 1912 b can be reduced as theoverall shape of the TOF boundary 1908 becomes evident. Hence the sizeof subsequent search region 1950 can be sized according to theconfidence level of the LIDAR in the estimated boundary location 1912 b.In one aspect a dynamically steered LIDAR can have a FOV with at leasttwo dimensions (e.g. an elevation dimension indicated by an elevationangle and an azimuthal dimension indicated by an azimuthal angle).

FIG. 20 illustrates two laser range finding systems 2010 a and 2010 b.Each of the laser range finding systems comprise a steerable laserassembly 2020 a and 2020 b operable to dynamically steer a laser beamaccording to laser steering parameters. Laser ranging systems (e.g.LIDARs) can have a pulsed laser or a continuous laser. Steerable laserassembly 2020 a has a pulsed laser and generates a discrete time seriesof laser pulses (e.g. 2030 a and 2030 b) illustrated in graph 2025 a.For example, pulses can be 5 nanoseconds in duration and occur every 1millisecond. Steerable laser assembly 2020 b is a continuous laser andgenerates a continuous wave illustrated in graph 2025 b. Continuouslaser ranging systems often modulate the amplitude (e.g. sinusoidalmodulation) of a continuous laser and measure the phase of the reflectedwave to calculate the range for a location (e.g. direction) in the fieldof view. It can be appreciated looking at the waveform of 2025 b thatthe amplitude peaks of the amplitude modulated waves can be consideredpulses of laser light. For the purposes of this disclosure a continuouswave laser generates one or more pulses (e.g. 2030 c) corresponding tothe peaks of the continuous amplitude modulated laser. Steerable laserassembly 2020 b can generate several pulses at a particular location.For example, pulses 2030 c and 2030 d can be generated at a firstlocation (e.g. direction) in the field of view of system 2010 b whilepulses 2030 e and 2030 f can be generated at a subsequent time andlocation.

A Low-Profile Vehicle-Integrated LIDAR

LIDARs often require direct visibility to objects being ranged. For thisreason LIDARs are often mounted high above the vehicle to obtain anunobstructed field of view. Several embodiments of the presentdisclosure can be used to provide a low profile LIDAR system with avehicle-integrated laser distribution system. A laser beam from a LIDARcan be transmitted into a cavity region underneath a body panel of avehicle and thereby guided beneath the body panel (e.g. roof) to a lensoperable to transmit or refract the beam into a curtain of coveragearound the vehicle. The interior reflectors and lenses can form a laserbeam guide. The laser beam guide can augment the limited direct field ofview of a fully or partially embedded LIDAR by providing awell-controlled indirect beam path (e.g. requiring several reflections).The output laser angle from the beam guide is a function of the inputbeam angle from the LIDAR. In this way the beam guide can utilize andmodify existing cavities behind body panels common in automotive designto guide and distribute laser beams for laser ranging. The beam guidecan extend LIDAR coverage into hard to reach parts of the FOV (e.g.parts of the FOV obscured by the roof or sides of a vehicle) whileallowing the LIDAR to remain low profile or embedded in the vehiclestructure.

In a first embodiment a thin laser beam guide can be housed below avehicle roof panel and comprise a narrow airgap and a set of opticalreflectors that are substantially horizontal and opposing. The laserbeam guide can be elongated in one or more directions, therebycontouring to the shape beneath a typical vehicle roof panel. A LIDARcan be located below the roof panel (thereby out of sight) and produce alaser beam that is guided towards the edges of the roof by the laserbeam guide. Once at the edge of the vehicle roof a laser beam can belaunched into the field of view at an output angle determined in part bythe input angle of the beam generated by the LIDAR. In the firstembodiment the laser beam guide can further comprise an output lens atthe outside edge of the beam guide that can function to refract thelaser beam downwards and provide laser coverage for the region close tothe vehicle.

In a second embodiment the beam guide can comprise a prismatic lenslocated around the perimeter of the vehicle roof. In the secondembodiment the LIDAR can transmit laser beams to a light guidecomprising of one or more reflectors and the prismatic lens. Thereflectors can be located on the outside of a roof panel and serve toguide a laser beam parallel to the plane of the vehicle roof towards alocation on the prismatic lens determined by the initial angle of thelaser beam. In a third embodiment a vehicle with a solid state LIDAR,having a limited field of view (e.g. 50 degrees) can use avehicle-integrated laser distribution system to guide laser beams from aportion of the FOV, thereby providing enhanced peripheral ranging from asingle LIDAR.

Several aspects provide a system to minimize the obstructed portion of aLIDAR FOV by providing an indirect path for reflection and/ortransmission of laser beams to objects beyond the direct field of view.Objects can be outside of the direct FOV either due to obstructions suchas vehicle body panels or due to the design limitations of the directfield of view. In one aspect, one or more of the reflectors or lenses inthe laser distribution system can be repositionable (e.g. motorized).This can enable the laser distribution to redistribute the resources ofa LIDAR for tasks such as parking or reversing.

Vehicle-Integrated Laser Range Finder Advantages

Several embodiments can reduce the profile of a LIDAR (e.g. height abovethe vehicle roof), while maintaining laser ranging capability in regionsbelow the horizon of the roofline, using a lens at the roof edge torefract laser light. In some embodiments, the LIDAR can be completelyhidden below a roof panel. Placement of the LIDAR partially or fullybelow a vehicle roof panel offers improved fuel economy, aestheticappeal and does not limit roof-rack options.

The disclosed techniques enable the LIDAR to be fully or partiallyembedded behind a vehicle body panel, thereby reducing the risk ofdamage or theft.

In another advantage, the disclosed technologies can be implemented toextend the FOV of a solid state LIDAR. Solid state LIDAR can have asmaller field of view (e.g. 40-60 degrees in the horizontal or azimuthalplane) relative to mechanical or rotating LIDAR (e.g. 360 degrees).Embodiments of the present disclosure can guide laser light to and fromlocations obscured by parts of the vehicle to the FOV of the LIDAR.Guiding a laser beam to locations beyond the unobstructed FOV of aLIDAR, provides greater utilization of the LIDAR and can reduce thetotal number of LIDARs required to provide full coverage around avehicle. The proposed techniques enable laser light to be guided in athin layer (e.g. a beam guide) behind a body panel. The beam guide hasthe advantage of keeping optical components (e.g. reflectors, lenses,and LIDARs) in a clean (e.g. dust-free), dedicated and hiddenenvironment. The proposed technologies can make better use of a singleLIDAR and potentially eliminates the need for others.

In another advantage, the present techniques can utilizes existingpanels as substrates for reflectors and existing cavities behind vehiclebody panels as the transport region for the laser beam thereby providinglaser guidance and direction changes with minimal additional weight orcomplicated light conducting mediums. In another advantage, thedisclosed technology provides a means to confine a laser beam in anarrow region behind a body panel, guide the laser beam towards the edgeof the body panel and transmit the laser beam into the regionsurrounding the vehicle at an output horizontal angle based on theinitial beam horizontal angle at the LIDAR. This ability to select theoutput angle of the laser based on the input angle is advantageous forcreating a second field of view that can be used to augment theunobstructed field of view of the LIDAR. In comparison the narrow natureof a fiber optic core makes recovering the input angle at the output ofa fiber optic cable practically impossible.

In another advantage, the reflectors and lenses that form the beam guidecan be placed in the traditional location of molding strips or theposition of a rear brake light. In another advantage, the laserdistribution system provides means to distribute laser light around avehicle in a controlled (e.g. sealed) environment such that the laserintensity can be greater than eye safe limits (e.g. ANSI-Z136) andtransmit the laser beam at a lower, eye-safe intensity (e.g. an expandedbeam) into the surrounding environment.

In another advantage, the disclosed laser distribution system canprovide an indirect FOV and a direct FOV that provide ranging of acommon object from two different directions, thereby reducing shadowingand improving object recognition. For example, a laser distributionsystem mounted behind a vehicle bumper can have a direct field of viewin front of the vehicle and can guide laser beams from part of the FOVusing a reflector assembly inside the bumper to lenses at the sides ofthe vehicle, thereby providing ranging of some of the region in front ofthe vehicle, within the direct field of view, from two differentperspectives.

In another advantage the disclosed technology provides guiding a laserbeam for laser ranging in a beam guide from a LIDAR to a lens. The beamguide can be a cavity and the cavity can serve multiple alternativevehicle functions such as carrying heated or cooled air around thevehicle (i.e. as the beam guide can be an air-conditioning duct). Forexample, the laser distribution system could be integrated with theducts to distribute air to the front or rear windshield of a vehicle.

In another advantage, embodiments of the present disclosure generatelaser pulses from a plurality of relatively inexpensive laserspositioned around a vehicle and use a beam guide to channel laserreflections to a centralized laser detector (e.g. photodetector) capableof performing laser ranging. In this way the more expensive laserdetector array (e.g. avalanche photo-diode array or single photonavalanche detector array) can receive reflections from several remoteFOVs through a process of guiding reflections behind the vehicle bodypanels.

A vehicle for the purpose of this disclosure is a machine operable togenerate a force to transport itself. Exemplary vehicles include, butare not limited to: cars, minivans, buses, motorcycles, trucks, trains,robots, forklifts, agricultural equipment, boats, drones and airplanes.

Passenger vehicles are a subset of vehicles designed to carry one ormore people. Exemplary passenger vehicles include, but are not limitedto: cars, minivans, buses, motorcycles, trucks, trains, forklifts,agricultural equipment, boats, and airplanes. FIG. 21A illustrates thata LIDAR 2120 a (e.g. model HDL-64E available from Velodyne LIDARs ofMorgan Hill, Calif.) can have a FOV 2115 comprising the set of alldirections along which the LIDAR can emit a laser. The FOV 2115 can bedescribed by a range of angles 2116 in a vertical plane (e.g. theelevation angle range or angle relative to the horizon) and a range ofangles 2118 in the azimuthal plane. FOV 2115 for LIDAR 2120 a istherefore the set of all possible directions (i.e. combinations ofelevation angle and azimuthal angles) for which the LIDAR can generate alaser beam. Angular ranges 2116 and 2118 can be with respect to axis ofrotation of LIDAR 2120 a.

Turning to FIG. 21B, LIDAR 2120 a can be mounted above vehicle 2110. TheLIDAR can generate a laser beam or pulses in one of many directions thattravel in a straight line beyond the bounds of the vehicle. A laseremitted in an unobstructed direction can travel in a straight line to anobject beyond the vehicle and can be reflected along the same straightline path. In FIG. 21B, a laser emitted in a large portion 2125 a of theFOV, characterized by angular range 2127 a, has direct line-of-site toobjects (e.g. person 2130) beyond the vehicle. The LIDAR FOV can alsohave an obstructed portion 2128 a (e.g. characterized by angular range2129 a). For example, the roof of a vehicle can form an artificialhorizon for a LIDAR by obscuring direct line of sight to objects inelevation angular range 2129 a. A laser beam emitted along an obstructeddirection cannot travel in a straight line to an object beyond thebounds of the vehicle. For the LIDAR 2120 a illustrated in FIG. 21B aportion 2128 a of the FOV, characterized by elevation angular range 2129a is obstructed by the vehicle 2110.

A LIDAR can comprise one or more lasers operable to transmit laser beamsor pulses and one or more reflection detectors (e.g. photodetectors). Inseveral LIDAR designs the laser(s) and the reflection detector(s) areco-located (e.g. model HDL-64E from Velodyne LIDARS) and thereby share acommon field of view. For the purpose of this disclosure an unobstructedFOV, or unobstructed portion of a FOV can be defined as the set of allunobstructed directions in the FOV (e.g. the set of all directionsformed by combining an angle in the range 2127 a with an angle in therange 2118 in FIG. 21A). An unobstructed direction can be a direction inthe FOV of the LIDAR for which an emitted laser beam or a received laserreflection can travel beyond the bounds of the vehicle. Conversely, forthe purpose of this disclosure the obstructed FOV is the set of alldirection in the FOV for which the laser beam cannot extend beyond thebounds of the vehicle (e.g. the set of all directions in the range 2129a and 2118 in FIG. 21A).

In other LIDAR designs (e.g. bistatic LIDAR) the laser(s) and thereflection detector(s) are separated (e.g. where the laser(s) are on theoutside of a vehicle and the reflection detectors are located on theroof of a vehicle). In this situation the LIDAR can have distinct laserFOV and reflection detector FOV. A laser FOV can be considered the setof all directions that a laser in a LIDAR can transmit a laser beam.Alternatively a LIDAR ranging region can be considered the portion of 3Dspace surrounding the LIDAR through which each laser can transmit alaser beam. For a bistatic LIDAR the laser (e.g. laser transmitter) FOVcan be divided into an obstructed and unobstructed portion comprisingthose directions where a laser can and cannot extend beyond the boundsof a vehicle respectively. Similarly, for a bistatic LIDAR thereflection detector FOV can comprise an obstructed and unobstructedportion. The obstructed portion of a reflection detector FOV can be thesubset of all directions in the detector FOV for which laser reflectionsfrom beyond the vehicle are obscured (e.g. by the vehicle, or objectsmounted to the vehicle) and can therefore not reach the reflectiondetector. Conversely, the unobstructed portion of a reflection detectorFOV can be the subset of all directions in the reflection detector FOVfor which laser reflections from beyond the vehicle are unobstructed andcan therefore reach the reflection detector in a straight line fromreflection locations.

In order to be effective many LIDAR need a large portion of the FOV tobe unobstructed. In FIG. 21B the placement of LIDAR 2120 a above theroof of vehicle ensures that the unobstructed FOV is greater than theobstructed FOV (e.g. angular range 2127 a is greater than 2129 a) andhence person 2130 can be detected, even when person 2130 is close to thevehicle and appears at relatively low angles relative to the horizon(e.g. −50 degrees relative to the horizon or 50 degrees below thehorizon.

FIG. 21C illustrates LIDAR 2120 a located directly on the roof ofvehicle 2110, thereby reducing the unobstructed FOV and increases theobstructed FOV. By lowering the LIDAR closer to the roof of vehicle 2110the obstructed portion 2128 b, characterized by angular range 2129 b,becomes larger relative to the unobstructed portion of the FOV 2125 b,characterized by angular range 2127 b. Low profile placement of LIDAR2120 a can therefore contribute to a large obstructed FOV (i.e. blindspots) and thereby fail to detect person 2130. A challenge for vehicledesigners is to provide a large unobstructed portion of the FOV whilesatisfying competing requirements (e.g. wind resistance, ergonomics,vehicle aesthetics and wear on the LIDAR) that benefit from closerintegration of the LIDAR with the vehicle.

In FIG. 21A the FOV 2115 of LIDAR 2120 a can be the set of alldirections along which LIDAR 2120 a can emit or receives a laser beam orpulse. FOV 2115 in FIG. 21A has a corresponding laser measurement regionencompassed by FOV 2115 (i.e. 3-D region of space surround a LIDARthrough which laser beams from the LIDAR can travel). In the context ofthe present disclosure a laser measurement region is the set of alllocations in space through which a laser emitted in the FOV can providea laser range measurement. Therefore the laser measurement region can bethe set of location through which a laser emitted in the FOV travelsuntil it reaches a surface operable to be non-transmitting to the laserbeam. After travelling through a laser measurement region beyond thevehicle a laser beam from LIDAR 2120 a laser beams can strike a set ofreflection locations.

Now consider that LIDAR 2120 a can generate a laser in one of manydirections that travel in a straight line beyond the bounds of thevehicle. However, LIDAR 2120 a can also emit a laser beam in a directionin the FOV that travels in an indirect path beyond the bounds of thevehicle, including at least one direction change after exiting theLIDAR. The reflected light from an indirectly illuminated object can bereceived by the LIDAR along the same indirect path.

For the purpose of this disclosure an unobstructed FOV can be dividedinto two subsets of directions; an indirect FOV and a direct FOV. Forthe purpose of this disclosure a direct FOV is defined as the set of alldirections in a FOV for which a laser beam can travel in a straight lineto or from a point beyond the bounds of the vehicle (i.e. direct paths).

For the purpose of this disclosure an indirect FOV is defined as the setof all directions in a FOV for which a laser beam can travel by anindirect path to or from a location in space beyond the bounds of thevehicle (e.g. requiring at least one direction change such as areflection of refraction). It can be appreciated that an unobstructedFOV can be the union (i.e. combination) of the direct FOV and theindirect FOV. In addition, with careful design a LIDAR can be closelyintegrated into a vehicle (e.g. close to the roof as illustrated in FIG.21C) and various embodiment of this disclosure can be used to convertsome or all of the obstructed portion of the FOV into an indirect FOV,thereby increasing the unobstructed FOV.

Similar to direct and indirect portions of the FOV the laser measurementregion surrounding a LIDAR, through which laser beams travel, can bedivided into a direct measurement region and an indirect measurementregion. In the context of the present disclosure a direct laser regionis the region of 3-D space beyond a vehicle encompassed by the directFOV of a laser in a LIDAR. The direct measurement region is in theunobscured line of sight of the LIDAR. For example, person 2130 in FIG.21B is in the direct FOV 2125 a of LIDAR 2120 a. Person 2130 istherefore located in the direct measurement region of 3-D spacesurrounding LIDAR 2120 a. Similarly, an indirect measurement region is ameasurement region of 3-D space beyond a vehicle in which a laser beamin the indirect portion of a FOV can perform a laser measurement. Forexample, consider a laser that is emitted from a LIDAR, diffracted by alens at the edge of vehicle 2110 and thereby travels through an indirectmeasurement region that includes person 2130 in FIG. 21C.

In the context of the present disclosure the set of direct reflectionlocations can be defined as the set of all locations encompassed by thedirect portion of laser FOV in a LIDAR (i.e. those locations that alaser beam travelling in a straight with a direction in the FOV canstrike. The set of ranging locations changes with the placement of theLIDAR. For example, in FIG. 21B some of the locations in the set ofdirect ranging locations include locations on person 2130. In anotherexample FIG. 21C illustrates that locations on person 2130 are notwithin the set of direct reflection locations of LIDAR 2120 a, becausethe roof of the vehicle 2110 to block person 2130 from the FOV. Hence inFIG. 21C a laser travelling in a straight line direction within the FOVcannot reach points on person 2130. In several embodiments of thepresent disclosure a vehicle-integrated laser distribution system canprovide reflections from indirect reflection locations (i.e. pointsbeyond the set of point encompassed by the FOV).

Solid state LIDAR can have a narrow FOV (e.g. 50 degree azimuthal range)and therefore require thereby several (6-8) LIDAR to provide adequatecoverage of directions and reflections in the local environment.Embodiments of the present disclosure provide for spreading the pointsin the narrow FOV using a beam guide, thereby provide a greater range ofreflection locations outside the range of direct ranging locations.

Several embodiments of this disclosure provide a vehicle-integratedlaser distribution system, that increases the indirect FOV, using alaser beam guide embedded on or behind the vehicle panels or frame. Thisapproach can thereby offset the reduction in direct FOV, that can occurwhen the LIDAR is more closely integrated by providing dedicated andsometimes complicated indirect laser paths forming an indirect FOV. Insome cases the indirect FOV can be increased by guiding the emittedlaser beam to a lens with a wider unobstructed FOV, while in otherembodiments the lens increases the indirect FOV by refracts the laserbeam.

In one aspect solid state LIDARs can have a more limited field of viewand embodiments of the present disclosure provide for guiding laserbeams to and from remote parts of a vehicle and thereby distributinglaser pulses beyond the FOV of the LIDAR. For example, a small range ofangles from the FOV can be distributed into a wider range of outputangles by an integrated laser distribution system and be used to performranging in a remote location (e.g. at the edge of a wheel-arch) on avehicle. The wider range of output angles provides for larger laserpulse spacing which can be useful when object detection is preferredover dense object profiling. For example, such a vehicle-integratedlaser distribution system could be used to devote several small portionsof a LIDAR FOV to serve as object detectors (e.g. curbs, lane markers)in the wheel arch areas.

FIG. 21D-F illustrate various embodiments of vehicle-integrated laserrange finding systems. In general a vehicle-integrated laser rangefinding system can comprise a light detection and ranging system (e.g. aLIDAR) and a beam guide designed to be integrated into a vehicle thatfunctions to guide at least some of the laser beams used by the LIDAR.The effect of the beam guide can be to enable the LIDAR to be placed ina more integrated, inconspicuous, protected, multifunctional location(e.g. a location servicing mutually exclusive FOV portions). A LIDAR canboth transmit and receive laser beams. One subset of vehicle-integratedlaser range finding systems can be vehicle-integrated laser distributionsystems, wherein laser beams transmitted by the LIDAR can be distributedthrough a vehicle integrated beam guide. A second subset ofvehicle-integrated laser range finding systems can be vehicle-integratedlaser reflection acquisition system, wherein laser reflections fromreflection locations in a local environment to the LIDAR are guided by avehicle-integrated beam guide to a laser detector in the LIDAR. TheLIDAR in a vehicle-integrated laser range finding system can be ascanned LIDAR (e.g. HDL-64E from Velodyne Inc. of Morgan Hill, Calif.),a flash LIDAR, a monostatic LIDAR or a bistatic LIDAR. In severalembodiments the beam guide can function to guide laser beams in a narrowrange of angles (e.g. 10 degrees of elevation angle) in a lighttransmitting region of the beamguide (e.g. a fully or partially enclosedcavity, or a defined portion of space on the outside of a vehicle) fromthe LIDAR to a lens at a remote end of the beam guide (e.g. at the edgeof the roof of a vehicle). At the remote end, the beam guide can have alens that spreads the narrow angular range into a wider or largerangular range than the input angular range at the LIDAR. In this way abeam guide in a vehicle-integrated laser distribution system can servethree functions; firstly accept laser beams in a narrow range of angles;secondly to guide the laser beams to the output end of the beamguidewhile conserving the narrow angular range and thirdly to transmit thelaser beams with a wider range of output angles. Several embodiment alsofunction to transmit the laser beams into laser ranging regions that areexclusive form the laser ranging regions accessible by the LIDAR alone.

Conversely, a beam guide in a vehicle-integrated laser reflectionacquisition system can serve three functions; firstly to accept laserbeams in a wide first angular range at a first end that is remote from aLIDAR (e.g. at a lens at an edge of a roof panel); secondly to focus thelaser beams into a narrower angular range and to guide the laser beamsto the LIDAR end of the beam guide; and thirdly to provide the laserbeams to the LIDAR in the narrow angular range while preserving arelationship between the direction of each laser beam angle in the wideangular range at the first end and the direction in the narrow angularrange at the LIDAR.

In one embodiment, a vehicle-integrated laser range finding systemcomprises a light detection and ranging system (LIDAR) located on avehicle, the LIDAR comprising a laser configured to generate a pluralityof laser beams, and a laser detector configured to detect the pluralityof laser beams; and a beam guide disposed on the vehicle, wherein thebeam guide is separate from the laser detector, the beam guidecomprising: at least one optical element to guide at least some of theplurality of laser beams between a first end and a second end of thebeam guide; and at least one optical element to change correspondingbeam directions for the at least some of the plurality of laser beams.For the purpose of this disclosure an optical element is a solidcomponent that is designed to transmit or reflects an incident laserbeam while changing an aspect of the laser beam. Exemplary opticalcomponents that transmit an incident laser beam include lenses,partially transparent mirrors, prisms, Fresnel lenses, opticaldiffusers, optical splitters, optical delay lines. Optical elements thattransmit laser beams can also refract the laser beam (e.g. change thedirection). Exemplary optical components that reflect an incident laserbeam include, reflectors, partially transparent mirrors, metalizedpolymer surfaces, polished metal surfaces, roughened or facettedreflective surfaces and electro-activated mirrors. Exemplary aspects ofa laser beam that can be changed by an optical element include, beamdirection, beam intensity, beam trajectory, beam divergence angle andconstituent electromagnetic frequencies (e.g. a prism refracts differentfrequencies by different amounts). A laser in a LIDAR can be configuredby arranging lasers at fixed elevation angles, setting angularvelocities for a laser trajectory, setting a laser pulse rate, durationor intensity.

FIG. 21D is an exemplary diagram of a vehicle-integrated laserdistribution system 2140, embedded in the roof portion 2135 of a vehicle2110. Vehicle-integrated laser distribution system 2140 can function todistribute laser beams (e.g. 2145 a) from a laser range finder (e.g.LIDAR 2120 a). The roof mounted laser distribution system of FIG. 21Dguides input laser beams (e.g. 2145 a) emitted from LIDAR 2120 a, usinga set of reflectors (e.g. 2150 a, 2150 b, 2150 c, 2150 d and 2150 e)arranged within a light transmitting region 2152 a (e.g. an enclosedcavity) underneath a roof panel 2155. The light transmitting region is aportion of the beam guide wherein laser beams can be guided from one endof the beam guide to another. Input beams (e.g. 2145 a) can be guided toa set of lenses (e.g. 2160 a and 2160 b) located at the edge of the roofwhere the beam can be transmitted, magnified, or refracted (e.g.refracted beam 2180 a). A beam guide (e.g. 2141 a) can comprise one ormore of the reflectors a cavity to transport a laser beam and a lens ata location remote (e.g. the perimeter of a roof panel or a rear brakelight assembly). In general, a range of input beam angles 2190 can bereflected (e.g. at 2150 e) and refracted or transmitted (e.g. at lens2160 b) to form a corresponding set of output beam angles 2195, inregions outside the direct field of view of the LIDAR. In the embodimentof FIG. 21D reflected light from the laser beams can travel along thereverse path and thereby provide an indirect FOV to LIDAR 2120 a. Theroof mounted laser distribution system 2140 of FIG. 21D can utilizeseveral aspects of the existing body structure of passenger vehicles.For example, reflectors (e.g. 2150 a and 2150 b) can be mounted to theflat opposing surfaces of body panels 2155 and 2156. Lenses 2160 a and2160 b can be located at the edge of the roof where many vehiclesalready have rear lights or molding strips (e.g. long often blackstrips) for hiding the joints of roof panels. LIDAR 2120 a can beembedded below the roof panel 2155. In some embodiments LIDAR 2120 a canhave little or no direct FOV when embedded and laser distribution system2140 provides an indirect FOV.

FIG. 21E illustrates a vehicle-integrated laser distribution system2140, attached on top of the roof of a vehicle, including a LIDAR 2120 aand a beam guide 2141 b, according to an embodiment of the presentdisclosure. The beam guide 2141 b comprises a light transmitting region2152 b, a lens 2160 b and a reflector 2150 b to guide laser beams in thelight transmitting region from the LIDAR to the lens. In the embodimentof FIG. 21E input laser beam or pulse 2145 b is refracted by lens 2160 ato form output beam 2180 b. Output beam 2180 b travels through a region2198 a that is beyond the range of regions accessible from the directFOV of LIDAR 2120 a (e.g. due to the design limitations of the LIDARFOV). Input beam 2145 c is reflected at reflector 2150 b and thentransmitted through lens 2160 b as output beam 2180 c. Output beam 2180c travels through a region 2198 b that is outside of the direct rangingregion of LIDAR 2120 a or outside of the direct FOV of LIDAR 2120 a(e.g. due to the artificial horizon formed by the roof panel 2155).

FIG. 21F is an exemplary diagram of a vehicle-integrated laserreflection acquisition system 2142, embedded in the roof portion 2135 ofa vehicle 2110. Vehicle-integrated laser reflection acquisition system2142 can function to acquire laser reflections (e.g. laser reflection2146 a) from objects around a vehicle. In one embodiment avehicle-integrated laser reflection acquisition system 2142 comprises aLIDAR 2120 b and a beam guide 2141 c. LIDAR 2120 b comprises a laserdetector 2121 having a FOV 2137 comprising a set of directions in whichthe laser detector can detect laser reflections. LIDAR 2120 b ispositioned on vehicle 2110 such that FOV 2137 comprises a direct portionof the FOV 2138 and an indirect portion 2139 that is obstructed (e.g. bythe roof panel) from directly receiving laser reflections from beyondthe vehicle.

LIDAR 2120 b is a bi-static LIDAR and further comprises one or morelasers 2143 a and 2143 b, located remotely from the detector 2121, totransmit laser pulses to a plurality of reflection locations beyond thevehicle. This bi-static arrangement enables one or more lasers to bemounted at a variety of points on the vehicle with different FOVs. Thelasers can reach a variety of overlapping or mutually exclusivereflection locations around the vehicle, thereby providing coverage thatcan be adapted to various purposes (e.g. parking) or hazard locations(e.g. blindspots). In FIG. 21F beam guide 2141 c is disposed on thevehicle, separate from the laser detector 2121, and configured (e.g.with reflectors 2150 a-d and lenses 2160 a-b) to receive laserreflections (e.g. reflection 2180 a) corresponding to the laser pulsesfrom reflection locations and to change, for each of the laserreflections, a corresponding input direction (e.g. input elevationangle) and to thereby guide the laser reflections to the laser detector2121 with output directions at the laser detector in the indirectportion of the FOV.

It can be appreciated that the vehicle-integrated laser range findingsystem of FIG. 21F provides an indirect reflection path for laserreflections from reflection locations outside of the direct FOV 2138 ofLIDAR 2120 b. Hence, laser reflections received in the indirect portion(e.g. portion 2139) of FOV 2137 arrive at the laser detector 2121 indirections that are related to their reflection locations (e.g. location2136) but have been changed by the beam guide. Circuitry such as 3-Dlocation calculator 2191, including input/output angle converter 2192can be used to calculate 3-dimensional coordinates of reflectionlocations corresponding to the laser reflections. This circuitry caninclude computer processors, mircocontrollers, and analog circuits. The3-D location calculator 2191 can be configured with a transfer functionthat relates the arrival direction or input angles of laser reflectionsat the beam guide (e.g. at lens 2160 a) to the angle or direction in theindirect portion of the FOV of laser detector 2121. The 3-D locationcalculator can process reflection data from laser reflections, includingthe reflection direction at the detector, identify an indirect subset oflaser reflections with directions in the indirect portion of the FOV(i.e. those reflections in need of angular conversion), process theindirect subset of laser reflections according to the transfer functionand thereby generate 3-dimensional coordinates 2193 of the reflectionlocations. The 3-dimensional coordinates 2193 of the reflectionlocations can be displayed in a point cloud.

In several embodiments, optical elements in the beam guide can bereconfigured based on a variety of factors such as vehicle location(e.g. urban streets or parking). The beam guide can therefore bereconfigured to change the relationship between input angles of laserbeams at a first end (e.g. at lens 2160 a) and a second end (e.g. atdetector 2121). In a vehicle-integrated laser distribution system thebeam guide can be reconfigured to change the relationship betweendirections in a laser FOV of a transmitted laser beam into the beamguide and the output direction of that laser beam form a second end ofthe beam guide remote from the laser. The 3-D location calculator canreconfigure the transfer function in response to the reconfiguration ofthe beam guide and calculate 3-dimensional coordinates 2193 of thereflection locations accordingly. For example, a set of reflectors in abeam guide can be reconfigured to provide obstacle avoidance while anautonomous vehicle is parking in a garage. The 3-D location calculatorcan access a computer memory to retrieve data to reconfigure a transferfunction used to relate laser reflections to 3-dimensional coordinatesof reflection locations for the reconfigured beam guide. In anotherembodiment the transfer function in the 3-D location calculator can bereplaced with a new transfer function obtained by calculation or frommemory based on data indicating the new state of a reconfigured beamguide.

FIG. 22A illustrates a beam guide 2141 b that functions to guide a laserbeam in an incident direction (e.g. 2145 b) to a lens 2160 a and therebytransmit an output beam 2180 b from the lens. Beam guide 2141 b canfurther function to generate the output beam 2180 b in a direction suchthat beam 2180 b strikes an indirect reflection location that is outsidethe direct ranging region but inside the indirect ranging region (i.e. apoint that cannot be reached by a laser from the LIDAR travelling instraight line direction in the set of directions forming the FOV). Forthe purpose of this disclosure the straight-line distance between wherethe laser beam (e.g. 2145 b) exits the LIDAR (e.g. 2120 a) to the pointthat the laser beam is transmitted from the lens is the defined as theguided distance (e.g. distance 2210). In some embodiments, the beamguide functions to provide an enclosed or semi-enclosed region to guidethe laser beam along the guided distance 2210. Unlike sealed lightassemblies (e.g. headlight or rear brake lights on passenger vehicles)the beam guide can function to guide the laser beam over large guideddistance around a vehicle (e.g. 30 centimeters, 1 meter or from thefront of a vehicle to the rear of a vehicle). Similarly, the beam guidecan function to distribute the laser beam from a centralized source orgather laser beams from around large and diverse portions of thevehicle. In the embodiment of FIG. 22A beam guide 2141 b with lens 2160a is attached to substrate 2220. Incident laser beam can travel close orparallel to the substrate. Substrate 2220 can be an exterior panel ofthe vehicle (e.g. roof panel 2155 in FIG. 21E). In FIG. 22B beam guide2141 c comprises two vehicle panels (e.g. panel 2156 and roof panel2155) a reflector 2150 a and a lens 2160 a. In the beam guide of FIG.22B the incident laser beam 2145 b from solid state LIDAR 2120 c,travels behind the front surface 2227 of a body panel (e.g. 2155). Thefront surface of the body panel can be defined as the surface betweenthe vehicle and the environment surrounding the vehicle. In anotheraspect at least one non-light transmitting interior surface (e.g. anopaque or reflective surface 2225) is located behind the front surface(e.g. 2227) of a body panel (e.g. 2155). In beam guide 2141 c areflector is attached to or embedded in interior surface 2225 behind thefront surface 2227. Reflector 2150 a serves to guide a range of inputbeams with a range of incident angles e.g. 2145 b to form acorresponding range of output beam angles. Lens 2160 a can refract orsimply transmit laser beam 2180 b. Lens 2160 a can function to seal thegap between panels 2156 and 2155 at the end of the beam guide. Interiorsurface 2225 of panel 2155 and reflector 2150 a can be formed byfunctionalizing panel 2155 with opaque or reflective coatings or tapes.Cavity 2152 a can be defined as the space or the region between theinterior surfaces 2255 and 2226 located behind the exterior surface 2227of body panel 2155. In the embodiment of beam guide 2141 c the cavity iselongated along the path of the laser beam (e.g. in the direction formedby a line between the laser input point at the LIDAR and the out pointat the lens). The cavity can be thin (e.g. 1 mm to 10 centimeters) inthe direction normal to the interior surface 2225 and can havesubstantially uniform thickness if surfaces 2225 and 2226 remainparallel along the direction of travel of the laser beam. Cavity 2152 acan be at least partially enclosed by body panels 2155 and 2156, therebykeeping the cavity free from dirt, or obstacles that can obstruct laserdistribution or gathering. For example, enclosing the LIDAR 2120 b incavity 2152 a enables the laser distribution path (e.g. for beam 2145 c)to be kept free of dust and foreign objects through the life of avehicle. Lens 2160 a can be an elongated strip at the edge of body panel2155 with a larger surface area than the aperture of LIDAR 2120 b,thereby providing increased immunity from dirt and debris building up onthe lens exterior.

Turning to FIG. 22C auto manufacturers have increasingly implementedsealed headlight units comprising reflectors, and lenses. Beam guide2141 d illustrates a sealed or semi-sealed beam guide comprising two ormore non-transmitting surfaces 2225 and 2226, lens 2160 a and one ormore reflectors (e.g. 2150 a and 2150 d) located on the substrate 2230.Non-light transmitting surfaces 2225 and 2226 can be part of one or moresubstrates 2230 (e.g. molded polymer or formed metal). Substrate 2230can be sealed to the lens similar to sealed headlights, therebyproviding a watertight seal designed to keep dirt and moisture fromentering into the sealed beam guide 2141 d. At the entrance to the beamguide LIDAR 2120 a can make close contact with the substrate 2230.Substrate 2230 can be attached to the vehicle frame (e.g. at 2240) usinga variety of attachment technologies (e.g. rivets, screws, spacers). Inone example sealed beam guide 2141 d can be a single metalized polymersubstrate similar to a headlight reflector, and designed to guide anincident laser beam to a lens.

In several embodiments a beam guide comprises a cavity in which lightcan travel, the cavity being located between two or more substantiallyopposing non-light transmitting surfaces located behind the frontsurface of a vehicle body panel. The beam guide further comprises anopening at a first end to accept a laser beam with an input angle and alens at a second end to transmit the laser beam, wherein upontransmission of the laser beam from the lens the laser beam travels inan output direction (e.g. direction of beam 2180 b) that is based on theinput direction (e.g. the direction of beam 2145 c) and strikes a pointoutside the set of direct ranging points. The laser beam can be guidedalong the cavity by one or more reflective portions of the two or moresubstantially opposing non-light transmitting surfaces.

FIG. 23 is an exploded view of a variety of components of avehicle-integrated laser distribution system in accordance with anembodiment of the present disclosure. Four elongated lenses 2160 a, 2160b, 2160 c and 2160 d are arranged at the edges of the vehicle roof.Lenses can be integrated behind the windows or windshields of thevehicle. For example, many vehicles integrate a lens for a third rearbrake light inside the rear windshield, where it is protected by thewindshield. Lens 2160 d could be similarly placed behind the windshield.In one embodiment one or more lenses can be existing lenses for brakelights or headlights. A set of reflectors can be arranged in twosubstantially opposing subsets (e.g. 2150 f and 2150 g) arranged onopposing side of a narrow (e.g. linch) cavity. Reflector subsets 2150 fand 2150 g can be metalized plastic similar to those used in headlightreflectors. In some embodiments reflector subset 2150 f can be attachedto roof panel 2155. For example, reflector subset 2150 f can bereflective tape adhered to locations on roof panel 2155. Reflectorsubsets 2150 f and 2150 g can be polished metal portions of the vehiclebody (e.g. panels) or frame (e.g. A pillar or B pillar). Cavity 2152 acan contain a wide variety of traditional structural support elementssuch as metal roof support 2310. In one aspect holes or openings 2320 inthe vehicle roof supports (e.g. 2310) can be strategically placed topermit laser beams to travel in the laser distribution system.

FIG. 24A illustrates a plurality of planes (e.g. 2410 a, 2410 b, 2410 c,2410 d, 2410 e and 24100, each representing a plurality of directionsalong which the indirect reflections from objects that are outside thedirect FOV of a laser LIDAR 2120 a can be provided to the LIDAR usingvarious components of a vehicle-integrated laser distribution system, inaccordance with an embodiment of the present disclosure. Each plane(e.g. 2410 a) comprises a plurality of output directions at a variety ofangles in the azimuthal plane and a constant angle in the elevationplane. Planes 2410 a-f also illustrate portions of the ranging region(i.e. the 3-dimensional space) through which laser pulses andreflections can travel beyond the vehicle to and from ranginglocations). FIG. 24B illustrates additional plane 2410 h operable toprovide laser reflections at low elevation angles in front of thevehicle and plane 2410 g operable to provide reflections from lowelevation angles behind the vehicle. These low elevation planes (e.g.2410 a) can be particularly beneficial for parking (e.g. in garages andcompact parking spots). Low elevation angle planes (e.g. 2410 a) alsohave the advantage that they emanate from a high point and can thereforeimage the entire way to the ground without the need to subtend a widearc in the manner that a side mounted LIDAR would.

FIG. 25 illustrates several components of a vehicle-integrated laserdistribution system, including a LIDAR and an elongated lens. Elongatedlens 2160 a can be placed at the edge of a vehicle body panel (e.g.2155). It is common in passenger cars to have molding strips at thejunction between a roof panel 2155 and a side panel 2510 and to coverthe joint between the panels. Elongated lens 2160 a can be located inthe junction region 2520 between roof panel 2155 and side panel 2510.This choice of placement enables a laser beams to be guided above theroof panel as illustrated in FIG. 25 or beneath the roof panel (e.g.2145 a in FIG. 21D). With reference to FIG. 25 and FIG. 26 lens 2160 acan have a variety of features operable to transmit laser beams in avariety of ways. For example, flat section 2510 can transmit an inputlaser beam 2145 b as an output beam 2180 e with the same direction andthereby contribute to the direct FOV. Input laser beam 2145 d can bemagnified by section 2520 of lens 2160 a and thereby create a largerlaser spot size 2180 d. The larger spot size 2180 d can be useful forobject detection by providing reflections from more of an object than asmall spot size. Input laser beam 2145 c can be reflected by reflector2150 b and can be refracted by section 2530 of lens 2160 a and createoutput beam 2180 c. FIG. 26 illustrates a vehicle-integrated laserdistribution system comprising a lens, a LIDAR and a reflector 2150 bintegrated into the roof panel 2155. In FIG. 26 output beam 2180 c cantravel through indirect laser measurement region 2610 outside of thedirect FOV and can reflect from an indirect reflection location (e.g.2620). In this way lens 2160 a integrated into vehicle 2160 a can extendthe range of reflection locations to locations outside the FOV of LIDAR2120 a, or compensate for a portion of the FOV that has been obscured bythe vehicle. In this way lens 2160 a can turn an otherwise obstructedportion of a FOV into an unobstructed portion by providing an indirectpath for laser reflections. Input beam 2145 e can travel in the directFOV beyond the vehicle. In one embodiment of the laser distributionsystem of FIG. 26 a majority of the FOV can be comprised of a direct FOVsimilar to traditional rotating LIDAR. At one or more angles ofelevation a range of azimuthal angles (e.g. 2190 in FIG. 25) caninteract with the vehicle integrated laser distribution system andthereby be distributed in a complex manner to adapted to the vehicleshape (e.g. diverting the beam around parts of the vehicle,concentrating or expanding the angular resolution to provide enhancesresolution in certain areas such as blindspots).

FIG. 27A is an exemplary diagram of an vehicle-integrated laserdistribution system, embedded in the roof of a vehicle, including alaser range finder and a beam guide, according to an embodiment of thepresent disclosure. LIDAR 2120 b can be a solid state LIDAR with nomoving parts such as the model S3 from Quanergy Inc. of Sunnyvale Calif.Solid state LIDARs often have a restricted azimuthal angular range inthe FOV (e.g. +25 degrees and −25 degrees from the forward facingdirection). As a result LIDAR 2120 b may not be able to provide coveragebehind towards the rear of vehicle 2110 within the direct FOV. LIDAR2120 b can function to provide ranging in a direct FOV 2125 c andprovide indirect ranging for objects in planes 2410 g and 2410 h thatare beyond the direct FOV but capture important blind spots (e.g. forvehicle lane changes). A laser distribution system can comprise LIDAR2120 b, a set of reflectors 2150 g and 2150 f and curves lens 2160 e.Reflector 2150 g can function to reflect some of the FOV of LIDAR 2120b, thereby guiding laser beams substantially parallel and in closeproximity to vehicle panel 2156, towards lens 2160 e, where they can betransmitted into plane 2410 g. For example, a particular azimuthal range(e.g. 20-25 degrees relative to the forward facing direction of LIDAR2120 b) and one or more elevation angles (e.g. +20 degrees relative tothe horizon) can be reflected by reflector 2150 g, refracted by lens2160 e and used to create indirect laser ranging plane 2410 g. In thisway a beam guide can provide a narrow (e.g. enclosed linch) region toguide laser pulses with a narrow angular range (e.g. 5-10 degrees)within a vehicle that can be expanded to a much larger angular range(e.g. 30-60 degrees) in an indirect laser measurement region surroundingthe vehicle.

In several embodiments one or more reflectors in the set of reflectorscan be repositionable (e.g. motorized). While many LIDAR have a fastspinning mirror to create the azimuthal angular range, mirrors in thelaser distribution system can be repositioned for the purpose ofchanging the laser measurement regions or planes (e.g. 2410 g) providedin the indirect FOV. The reflectors can be repositioned in response tochanges in the state of the vehicle (e.g. shifting into reverse,traveling above a speed threshold). Reflectors can also be repositionedin response to location data or sensor data (e.g. camera images or radardata), corresponding to particular tasks (e.g. parking) or hazards (e.g.curbs or vehicle wing mirrors). For example, in response to dataindicating that vehicle 2110 is parking the laser distribution systemcan reposition reflectors 2150 g for the task of parking. Reflector 2150g can be repositioned such that input laser beams are directed at asection (e.g. 2530) of lens 2160 e operable to refract the laser beam ata low elevation angle (e.g. towards the ground). In this way a laserdistribution system can be dynamically adapted to watch for situationspecific hazards (e.g. objects in a garage while parking). The samelaser distribution system can adapt reflectors (e.g. 2150 g and 2150 h)for driving on the highway by raising the elevation of planes 2410 g and2410 h to provide blind spot coverage extending a longer distance fromvehicle 2110. Planes 2410 g and 2410 h can also be extended to providerear-view coverage.

FIG. 27B is a diagram of an integrated laser distribution systemcomprising LIDAR 2120 a and lens 2160 e. Lens 2160 e refracts light in anarrow range of elevation angles in the FOV of LIDAR 2198 a into acurtain shape plane 2410 i. Curtain shaped plane 2410 i can have a smalloutput angular range (e.g. 2195) corresponding to the input angularrange (e.g. 2190) operable to strike the lens 2160 e. However Lens 2160e can provide a wide azimuthal range (e.g. 2180 degrees as illustratedin FIG. 27B). In this way plan 2410 i can be very efficient at detectingthe range of objects close to vehicle 2110, requiring only a smallelevation range. The elevation range can be selected from the obstructedportion ( ) of the FOV. Hence the design of FIG. 27B provides efficientrepurposing of a portion of the obstructed FOV to image objects (e.g.people, curbs or objects in a cluttered home garage) close to the sidesof the vehicle 2110. In comparison, a side-mounted LIDAR (e.g. 2120 d)requires a large elevation angular range (e.g. 2116) and a largeazimuthal range (not illustrated) to provide ranging in the same region(e.g. 2125 d) of the vehicle 2110.

FIG. 27C illustrates another embodiment of a laser distribution systemcomprising a LIDAR 2120 a embedded partially beneath the roof of vehicle2110 and a lens 2160 f to provide laser ranging in a plane 2410 i beyondthe direct FOV of the LIDAR. In the embodiment of FIG. 27C lens 2160 fand a portion of the LIDAR FOV are embedded beneath the roof of vehicle2110. This design enables lens 2160 f to be integrated below theroofline (e.g. behind a rear windshield). This design also enables thelaser distribution system to use the lens associated with a brake lightas some or all of lens 2160 i. A portion of the FOV of LIDAR 2120 a canbe distributed below the roof panel of vehicle 2110 to lens 2160 f.Another portion of the LIDAR FOV can be above the roof panel and providea direct FOV.

FIG. 28 is an exemplary diagram of an integrated laser distributionsystem behind the front panels (e.g. bumper, hood and grille) of avehicle and providing an indirect FOV for a LIDAR. Solid state LIDAR2120 b can have a FOV characterized by an angular range 2118 in theazimuthal plane and an angular range in the elevation plane (not shownin FIG. 28). A direct FOV characterized by angular range 2127 c canprovide direct ranging of objects in laser measurement region 2125 c. Asubset (e.g. subset 2820) of angular range 2118 can be devoted toproviding indirect ranging in one or more indirect laser measurementregions (e.g. 2810) that are inaccessible by the direct FOV (i.e. therange of angles that the off-the-shelf LIDAR can provide). The indirectFOV can comprise the set of directions with azimuthal angle in the range2820 and elevation angles in the FOV of LIDAR 2120 b (e.g. +20 degreesto −20 degrees from the horizon). In the embodiment of FIG. 28 laserbeams in the azimuthal range 2820 are guided by a set of reflectors(e.g. 2150 h, 2150 i, 2150 j, 2150 k and 2150 l) located behind thefront panel 2805 (e.g. the front bumper) of vehicle 2110. Laser beams inazimuthal range 2820 are guided substantially parallel to the frontpanel 2805. The set of reflectors can be a disposed on a plasticsubstrate similar to the reflectors in a headlight assembly. In theembodiment of FIG. 28 the guided laser beams in azimuthal angular range2820 can be reflected by a final reflector 2150 m and lens 2160 f togenerate an output azimuthal angular range 2830 into region 2810. Someof the reflectors (e.g. 2150 h, 2150 i, 2150 j, 2150 k and 2150 l) canhave fixed positions and can therefore be permanently positioned whenthe vehicle is constructed. For example, reflectors can be embedded intothe foam impact absorbers (e.g. foam blocks) within a vehicle bumper.Other reflectors such as 2150 m at the input or output of the beam guidecan be repositionable (e.g. by manual positioning or by motorizedplacement). These movable or motorized reflectors provide fordynamically reconfiguring the angular range 2830 and thereby generatingdifferent regions 2810. In several embodiments region 2810 can beexclusive from the region (e.g. 2125 c) accessible by the direct FOV(characterized by angular range 2127 c) and in some cases can be outsideof the region directly assessable by the entire FOV of LIDAR 2120 b(characterized by angular range 2118). In another embodiment continuousreflectors 2150 o and 2150 n can be arranged on opposite sides of a thincavity beneath body panel 2805 and can project a laser beam through lens2160 g.

FIG. 29A illustrates a process 2900 for providing a laser range finderwith extended coverage (i.e. increasing the total laser measurementregion or the unobstructed FOV) using a vehicle mounted beam guideaccording to aspects of the technology.

At block 2910 a LIDAR is provided, attached to a vehicle, the LIDARhaving a field of view. At block 2920 an adapter is provided, theadapter being positioned at least partially within the FOV of the LIDAR.The adapter can function to transmit laser beams from at least a portionof the FOV into a beam laser beam guide attached to the vehicle.

At block 2930, a laser in the LIDAR generates a laser beam with an inputdirection within the FOV.

At block 2940 the laser beam is transmitted into a beam guide, the beamguide being separate from the LIDAR, the beam guide comprising a lens, afirst set of reflectors and a second set of reflectors.

At block 2950 the laser beam is guided behind a body panel on thevehicle in a laser transmitting medium between the first and second setof reflectors. In some embodiments of method 2900 the first and secondset of reflectors can each comprise a single reflector. In otherembodiments each reflector in the first set of reflectors is a planarsurface on substrate (e.g. polymer or metal) that is common to the firstset of reflectors. In other embodiments each reflector in the first andsecond set of reflectors are surfaces or portions on a common substrate(e.g. a single molded polymer substrate with the first and second setsof reflectors attached to opposing surfaces). In some embodiments thefirst set of reflectors can comprise a single first reflector, thesecond set of reflectors can comprise a single second reflector and thefirst and second sets of reflectors can share a common substrate (e.g. abeam guide formed from a single polymer or metal substrate with tworeflectors comprising elongated reflective strips that guide a laserbeam). In some embodiments the first and second set of reflectors canguide the laser beam across a significant portion of a body panel suchas at least 50 centimeters.

At block 2960 the laser beam is transmitted through the lens in anoutput direction, wherein the output direction is based on the inputdirection, and wherein the beam guide causes the laser beam to strike areflection location beyond the bounds of the vehicle exclusive from theset of direct reflection locations (i.e. exclusive from the set ofdirect ranging points where laser range measurements can be performed bya laser beam travelling in a straight line from the LIDAR).

FIG. 29B illustrates an alternative process 2905 for providing a laserrange finder with extended coverage using a vehicle mounted beam guideaccording to aspects of the technology.

At block 2945, the laser beam is transmitted into a beam guide, the beamguide being separate from the LIDAR, the beam guide comprising a lensattached to the vehicle, wherein the beam guide comprises means toconvert a range of input laser beam angles at the LIDAR into acorresponding range of output beam angles at the lens. The means can bea reflector in the beam guide, a lens refracting the laser beam, aplurality of reflectors or a plurality of lenses or prisms. At block2965 the laser beam is transmitted through the lens attached to thevehicle in an output direction, wherein the output direction is based onthe input direction and wherein the output direction causes the laserbeam to travel through a point beyond the bounds of the vehicleexclusive from the set of points reachable in a straight line by a laserbeam with a direction in the field of view.

FIG. 38A illustrates a LIDAR 3801 comprising LIDAR electronic circuitry3820, adapter 3810 and rear housing 3830. LIDAR 3801 can have a FOVcomprising the set of all directions in which LIDAR 3801 can transmitlaser beams. Adapter 3810 can be positioned infront of the LIDARelectronics 3820 and can function to adapt, configure or customize LIDAR3801 to a specific set of beam guides (e.g. the beam guides disposed ina specific model or shape of vehicle) as part of a vehicle-integratedlaser distribution system or vehicle-integrated laser reflectionacquisition system. LIDAR electronics 3820 can include an optical phasedarray (OPA) to generate a laser beam in a range of directions formingthe FOV. LIDAR 3801 can transmit a first subset of laser beams directlyinto the surroundings to perform direct laser ranging of objects infrontof the LIDAR electronics 3820. Adapter 3810 can have a front surface3835 with portions that are transparent to the laser beam emitted byLIDAR electronics 3820, that function to facilitate direct laserranging.

Adapter 3810 can function to transmit a second subset of laser beamsinto one or more laser beam guides. One or more openings or transparentwindows 3840 a-c, transparent to the laser beam (e.g. glass) cantransmit laser beams into one or more beam guides (e.g. beam guide 2141a in FIG. 21D or beam guide 2141 b in FIG. 22A). One advantage ofadapter 3810 is that a vehicle manufacturer can select from a variety ofstandard or custom adapters to match the number and arrangements oflaser beam guides in the integrated laser distribution system. A familyof standardized or customized adapters can be designed to work with acommon LIDAR electronic circuitry 3820. In this way, a LIDAR maker candevelop and refine single a LIDAR electronics assembly and vehiclemanufacturers can use basic knowledge of the FOV associated with theLIDAR electronics 3820 (e.g. the total number of points per scan, or theazimuthal and elevation angular ranges in the FOV) to develop or selectan adapter 3810. Similarly, a vehicle manufacturer can use an adapter3810 to guide the design of various beam guides (e.g. the placement ofreflectors e.g. 2150 l in FIG. 28) to capture the laser beams from theadapter 3810. Adapter 3810 can have features similar to a radiofrequency connector for guiding radio frequencies or microwaves. Adapterfeatures can include connector shells to ensure spatial registration ofthe beam guides relative to the adapter and attachment points to mountthe adapter to the vehicle and/or to the LIDAR.

FIG. 38B illustrates a LIDAR adapter 3810 can have a surface 3850operable to transmit a laser beam in a direct FOV and one or moresurfaces (e.g. 3860 a and 3860 b) operable to reflect or refract a laserbeam 3870 in an output direction 3875 into a beam guide.

FIG. 38C illustrates that adapter 3810 can provide a direct portion ofthe FOV 3880 and indirect portion of the FOV 3890 a and 3890 b can bereflected or refracted at surfaces (e.g. 3860 a and 3860 b in FIG. 38B)and guided to form angular ranges 3895 a and 3895 b operable to betransmitted into laser beam guides.

FIG. 39 illustrates a field of view of a LIDAR, with a direct field ofview and an indirect field of view providing laser reflections fromseveral regions associated with the vehicle outside of the rangingregion provided by direct line of site of the LIDAR. A laser beam fromLIDAR 110 can be transmitted in a direction within the direct FOV 3980and travel in a straight line direction to points (e.g. 150 d or 150 e)within the set of all direct ranging points. The FOV 3910 of LIDAR 110also contains an indirect FOV comprising laser beams guided to regions3890 a and 3890 b. For example, in FIG. 39 azimuthal angles in the range0-10 degrees and 50-60 degrees can strike reflectors (e.g. 3860 a and3860 b in FIG. 38B) respectively and be transmitted through openings inthe adapter (e.g. 3840 a in FIG. 38A) into a laser beam guide.Reflections from points outside of the set of direct ranging points(i.e. the set of all points that a laser travelling in a straight linecan reflect from) can provide indirect ranging regions such as blindspots 3920 a and 3920 b, forward low elevation 3920 c and rearreflections 3920 d. Indirect regions 3890 a and 3890 b can be selectedto overlap with obstructed portions of the integrated LIDAR design.Hence adapter 3810 in FIG. 38A can provide effective repurposing ofobstructed portion of the FOV of a LIDAR, thereby reducing the totalnumber of LIDARs needed to provide complete vehicle coverage.

Laser Range Finder with Dynamically Positioned Detector Aperture

FIG. 30A illustrates a related technology in which a dynamically steeredlaser range finder 3010 (e.g. a LIDAR or 3D laser scanner) uses aspatial light modulator 3030 to create an electronically controlledaperture (e.g. opening) in the field of view of the laser receiver, thatis electronically positioned based on data indicating the direction of acorresponding steerable laser. One challenge for LIDAR, is discerninglaser reflections within a laser detector field of view (FOV) that cancontain a variety of light emitting or high brightness objects.Mechanically steered LIDAR (e.g. HDL-64E from Velodyne LIDARs or MorganHill Calif.) can point the laser transmitter (e.g. a laser diode) andfocus the laser detector (e.g. a PIN photodiode) at a small region ofspace along the direction the laser travels. This effectively focusesthe LIDAR laser detector in a particular direction relative to the lasertransmitter. The mechanical LIDAR transmitter and laser detector canthen be rotated around an axis to sweep out a 360 degree field of view.The advantage of this approach is that the laser detector is alwayspointed in the direction to receive the laser reflection. As aconsequence the laser detector in a mechanical LIDAR can be designedwith considerable immunity to bright light sources (e.g. the sun orvehicle headlights) outside of the instantaneous direction that thelaser detector is pointing.

In contrast, the laser detector in a solid state LIDAR (e.g. the modelS3 from Quanergy Inc. of Sunnyvale Calif.) can receive light from awider instantaneous field of view. For example, a solid state LIDAR witha 50 degree FOV in the azimuthal plane can steer a laser beam within theFOV but may receive light from all points of the FOV at once. In thissituation the laser detector can be susceptible to light sources fromall parts of the FOV at once. This can lead to photon saturation and canpreclude the use of more cost effective laser detector electronics suchas charge coupled device (CCD) arrays. CCDs typically have low photonsaturation charge. Because the photon saturation charge of CCD is small,if this saturation level is reached then the light intensity will besaturated. Photodiode arrays (PDA) have greater photon saturation thanCCDs and are used in many LIDARs today. Increasingly LIDARs are beingused in autonomous vehicles and it is considerably advantageous toimprove immunity of the LIDAR laser detector to bright light sources(e.g. headlights and sun) as well as other laser sources (e.g. otherLIDARs and denial-of-service attacks).

In one embodiment of the present technology an electronically steerableaperture is provided for a LIDAR laser detector that dynamically limitsthe portion of the laser detector FOV that can receive light based onthe anticipated position of a corresponding laser. The electronicallysteerable aperture can be a spatial light modulator (SLM) comprising aplurality of segments with electronically controllable opticaltransparency (e.g. liquid crystal array segments). A subset of segmentscan be darkened in order to block light from parts of the FOV of thelaser detector beyond the portion that is estimated to contain thereflected light from a corresponding laser. Turning to FIG. 30A and FIG.30B a dynamically steered laser range finder 3010 can have a steerablelaser transmitter 3015, such as an optical phased array (OPA). Steerablelaser transmitter 3015 can comprise a laser, a laser splitter, amultimode interference coupler, an optical phase shifter (e.g. linearohmic heating electrodes) an out of plane optical coupler to combine thesplit, phase-shifted beams into an output laser beam pointed in asteerable direction. Dynamically steered laser range finder 3010 canhave a photodetector 3020 (e.g. a PIN photodiode, avalanche photodiodeor CCD array). A spatial light modulator (SLM) can be placed in front ofthe photodetector 3020 (e.g. in the FOV of photodetector 3020). The SLMcan comprise a plurality of segments with electronically controllabletransparency (e.g. segment 3032). In an exemplary SLM the segments canbe formed with several components commonly found in an LCD array such asa glass substrate with indium tin oxide (ITO) electrodes to define thebounds of each segment, a liquid crystal layer, light polarizers andcolor filters operable to select a wavelengths range containing thelaser wavelength. Dynamically steered laser range finder 3010 cancontain a lens operable to focus light fromf the surrounding area ontothe photodetector 3020. Dynamically steered laser range finder 3010 cancontain control circuitry 3025. Control circuitry 3025 can function toreceive or generate laser steering parameters indicating how the lasershould be steered (e.g. directions, paths, or regions to scan with thelaser). Control circuitry 3025 can further function to generate commandsor signals to the steerable laser transmitter 3015 instructing thesteerable laser transmitter to generate a laser beam in a direction.Control circuitry 3025 can further function to generate an aperture 3060a with the SLM 3030. The aperture can comprise a non-zero subset of thesegments (e.g. 3032) that block light from a first portion of the FOV ofphotodetector 3020 from reaching photodetector 3020 and thereby transmitlight from a small second portion of the FOV that is selected totransmit light based on data indicating the direction of the laser. Inthe embodiment of FIG. 30A the blocked portion of the FOV can begenerated by applying a voltage to a non-zero subset of theelectronically controlled segments thereby rotating the liquid crystalrelative to one or more polarizer layers and blocking light from passingthrough the segment. Hence, a large subset of the segments can beelectronically controlled to block light from parts of the FOV andthereby block light beams (e.g. 3070) from objects such as vehicles 3075and the sun 3080.

FIG. 30B illustrates a photodetector 3020 and a SLM 3030. A portion ofthe FOV of photodetector 3020, represented by the range of angles 3085can receive light through an aperture 3060 a in the SLM. Another portionof the FOV of photodetector 3020, characterized by the range of angles3090 is blocked by the darkened subset of segments surrounding thetransmitting portion of the aperture 3060 a.

FIG. 31 illustrates several components of dynamically steered laserrange finder 3010. Control circuitry 3025 can include a laser steeringparameter generator/modifier 3110 operable to receive or generate lasersteering parameters for steerable laser transmitter 3015. For example,laser steering parameter generator 3110 can receive high levelinstructions to generate a laser beam with 10 milliradian beamdivergence, a spot size of 5 millimeters radius and scan the laser beamfrom left to right and from top to bottom within a transmitter FOV at ascan rate of 10 Hz. Alternatively, laser steering parametergenerator/modifier 3110 can generator or modify laser steeringparameters such as a laser a scan path, a series of way points, a seriesof laser pulse locations or the bounds of a region in the transmitterFOV in which the laser transmitter is to perform a laser scan with aspecified point density or scan rate. In one aspect laser steeringparameter generator/modifier can receive or generate high levelinstructions (e.g. a desired laser scan pattern) and can transmit thedesired laser scan parameters to a laser positioner circuit 3120operable to generate the signals necessary to generate a laser beam atthe desired locations. In another aspect the same information indicatingthe current or near-future direction of the steerable laser can beprovided to an SLM aperture positioner circuit 3130. SLM aperturepositioner circuit 3130 can be a driver circuit for the plurality ofelectronically controllable segments in SLM 3030. SLM aperturepositioner circuit 3130 can comprise one or more transistors, orintegrated circuits. In one aspect of several embodiments the SLMaperture positioner 3130 can combine indications of the laser positionin the FOV from either laser positioner 3120 or parameter generator 3110with feedback from laser detector 3020 regarding the amount of light(e.g. degree of photon saturation) reaching the laser detector. In thisway, during periods of intense ambient light, SLM aperture positionercan narrow the aperture to include only the region of the FOV with ahigh probability of containing the reflection from laser beam 3040. Inone embodiment control circuit 3025 can include laser steering parametergenerator/modifier 3110, laser positioner 3120 and SLM aperturepositioner 3130. In one embodiment control circuit 3025 can control theSLM aperture through the use of a simple lookup table for apertureposition (e.g. 3060 a) corresponding to a laser beam direction (e.g.direction of beam 3040 within the laser FOV).

FIG. 32 illustrates some alternative aperture shapes. Aperture 3060 b iswider than 3060 a in FIG. 31 and can therefore permit light in a widerrange of angles 3085 to reach the laser detector. Aperture 3060 b can beuseful of the direction of the reflected laser pulse 3050 is onlyapproximately known or if incident laser beam 3040 has a wide beamdivergence. Aperture 3060 c illustrates a slot aperture, useful if thelaser is being scanned from left to right across the FOV of the laserdetector at a constant elevation angle. Aperture 3060 d is a very wideaperture with only a non-zero subset of 5 segments 3210 that areelectronically controlled to block light from a small portion of theFOV. Aperture 3060 d can be useful when SLM 3030 is required to blocklight from a specific part of the FOV (e.g. the sun or an oncoming car'sheadlights).

FIG. 33 illustrates several components of an exemplary laser rangefinder 3010 in accordance with an embodiment of this disclosure. Laserrange finder 3010 can contain a laser steering parameter generator 3110to generate laser steering parameters based on processed sensor datafrom sensor data processor 3375. Laser range finder 3010 can contain alaser positioner 3120 to generate a laser pulse or steer a laser beam atone or more locations in the FOV based on the laser steering parameters.Electronically steered laser positioner 3120 can include one or moreoptical delay lines, acoustic or thermally based laser steeringelements. Laser range finder 3010 can contain a laser transmitter 3015to produce one or more laser beam 2440 at one or more locations in theFOV determined by the laser positioner 3110. The laser generator can beone or more laser diodes, near infrared lasers. Laser positioner 3120and laser transmitter 3015 can be combined onto a chip-scale opticalscanning system such as DARPA's Short-range Wide-field-of-view extremelyagile Electronically steered Photonic Emitter (SWEEPER). Laser rangefinder 3010 can generate on or more pulses with incident laser beam3040. Laser range finder 3010 can receive one or more laser reflections3050 from incident laser beam 3040. SLM aperture positioner can receivedata from laser steering parameter generator 3110 indicating thedirection of laser beam 3040. In various embodiments data regarding theposition of laser beam 3040 can be data about an upcoming or futurelaser pulse, can indicate a region of the FOV that in which the laserpointed or will be pointed in the future or can be a instructionregarding where to place the aperture. Laser range finder 3010 cancontain a photodetector 3020 to detect reflected light from the laserpulses or continuous laser beam. Photodetector 3020 can include one ormore photodiodes, avalanche photodiodes, PIN diodes, charge coupleddevice (CCD) arrays, amplifiers and lenses to focus the incoming lightfrom a narrow part of the FOV where the reflected light is anticipatedto come from.

Laser range finder 3010 can contain a time of flight calculator 3355 tocalculate the time of flight associated with a laser pulse striking anobject and returning. The time of flight calculator 3355 can alsofunction to compare the phase angle of the reflected wave with the phaseof the outgoing laser beam and thereby estimate the time-of-flight. Timeof flight calculator can also contain an analog-to-digital converter toconvert an analog signal resulting from reflected photons and convert itto a digital signal. Laser range finder 3010 can contain an intensitycalculator 3360 to calculate the intensity of reflected light. Time offlight calculator can also contain an analog-to-digital converter toconvert an analog signal resulting from reflected photons and convert itto a digital signal.

Laser range finder 3010 can contain a data aggregator 3365 to gatherdigitized data from time of flight calculator 3355 and intensitycalculator 2460. Data aggregator can gather data into packets fortransmitter 3370 or sensor data processor 3175. Laser range finder 3010can contain a transmitter 3370 to transmit data. Transmitter 3370 cansend the data to a computer for further analysis using a variety ofwired or wireless protocols such as Ethernet, RS232 or 802.11.

Laser range finder 3010 can contain a sensor data processor 3375 toprocess sensor data and thereby identify features or classifications forsome or all of the FOV. For example, data processor 3375 can identifyfeatures in the FOV such as boundaries and edges of objects usingfeature identifier 3380. Data processor 2475 can use feature localizer3385 to determine a region in which the boundaries or edges lie.Similarly a classifier 3390 can use patterns of sensor data to determinea classification for an object in the FOV. For example, classifier 3390can use a database of previous objects and characteristic featuresstored in object memory 3395 to classify parts of the data from thereflected pulses as coming from vehicles, pedestrians or buildings.

FIG. 34 illustrates a process 3400 for operating a spatial lightmodulator 3030 to generate an aperture, based on data indicating theposition of laser beam reflections in the FOV of a laser range finder3010 and specifically the FOV of a photodetector 3020. At block 3410 aphotodetector 3020 is provided with a field of view (e.g. a set ofdirections in which the photodetector can receive light). A spatiallight modulator is provided at a location at least partially within thefield of view. The spatial light modulator comprises a plurality ofsegments (e.g. LCD sections) with electronically controllabletransparency.

At block 3420 data is obtained indicating the direction of a laser beam.The laser beam can be generated by an electronically steerable lasertransmitter such as an optical phased array (OPA). At block 3430 anon-zero subset of the plurality of segments is selected, based on thedata indicative of the direction of the laser beam. At block 3440 thetransparency of the selected subset of segments is electronicallycontrolled. At block 3450 an aperture in the spatial light modulator isgenerated that transmits light through a portion of the field of viewthat contains reflections from the laser beam. The aperture can be atransparent section in the spatial light modulator surrounded at leastin part by one or more non-light transmitting segments from theplurality of segments.

Keepout Mask Area

In a related technology FIG. 35 illustrate a laser range finder 110 thatcan be dynamically steered to avoid transmitting the laser beam into aregion of the field of view containing the, body, head or eyes of one ormore people. Laser range finders (e.g. LIDAR and 3-D scanners aregaining popularity due in part to their ability to develop up-to-datedepth maps for autonomous vehicles. LIDAR has also been proposed as ameans to estimate occupancy and peoples locations in smart buildings.Correspondingly there is the potential for people to experienceincreased instances of sporadic transmission of lasers towards theireyes (e.g. a person sitting in a cubical during a workday with an indoorLIDAR system). In autonomous vehicle there is interest in increasing thelaser intensity to improve LIDAR range (e.g. from 100 m to 200 m).

Recently, advancements in electronically-steerable lasers and phasedarray laser beam forming have made it possible to dynamically steer alaser within a FOV. A steerable laser can be mechanically-steerable(e.g. containing moving parts to redirect the laser) orelectronically-steerable (e.g. containing an optical phased array toform a beam in one of many directions). For the purpose of thisdisclosure a steerable laser is a laser assembly (e.g. includingpositioning components) that can change the trajectory or power level ofa laser beam. For the purpose of this disclosure a steerable laser isdynamically steerable if it can respond to inputs (e.g. user commands)and thereby dynamically change the power or trajectory of the laser beamduring a scan of the FOV. For the purpose of this disclosure dynamicallysteering a laser is the process of providing input data to a steerablelaser that causes the laser to dynamically modulate the power ortrajectory of the laser beam during a scan of the FOV. For example, alaser assembly that is designed to raster scan a FOV with a constantscan rate and pulse rate is acting as a steerable laser but is not beingdynamically steered. In another example the previous steerable laser canbe dynamically steered by providing input signals that cause thesteerable laser to generate a variable laser power at locations in theFOV, based on the input signals (e.g. thereby generating an image on asurface in the FOV). A trajectory change can be a direction change (i.e.a direction formed by a plurality of pulses) or a speed change (i.e. howfast the laser is progressing in a single direction across the FOV). Forexample, dynamically changing the angular speed across a FOV of a pulsedlaser with a constant direction causes the inter-pulse spacing toincrease or decrease thereby generating dynamically defined laser pulsedensity.

In the context of the present disclosure many rotating LIDAR do notcomprise dynamically steerable lasers since neither the power nor thetrajectory of the laser beam is dynamically controllable within a singlescan. However a rotating or mechanical LIDAR can be dynamically steered,For example, by providing input data that causes the laser todynamically vary the laser pulse rate within a scan of the FOV, sincethe net result is a system that can guide or steer the laser to producea non-uniform density laser pulse pattern in particular parts of theFOV.

Recently, electronically scanned LIDAR such as the model S3 fromQuanergy Inc. of Sunnyvale, Calif. have been developed. Thesesolid-state electronically scanned LIDAR comprise no moving parts. Theabsence of angular momentum associated with moving parts enables dynamicsteering of one or more lasers in electronically scanned solid-stateLIDAR systems.

In many laser range-finding systems the laser is periodically pulsed andthe exact pulse location in the FOV cannot be controlled. Neverthelesssuch a periodic pulse laser can be used with the present disclosure toproduce a complex shaped region of higher pulse density than the areasurrounding the region by increasing the laser dwell time within theregion. In this way a periodically pulsed laser will produce a greaterdensity of pulses in the complex shaped region. Other laser rangefinding systems transmit a continuous laser signal, and ranging iscarried out by modulating and detecting changes in the intensity of thelaser light. In continuous laser beam systems time of flight is directlyproportional to the phase difference between the received andtransmitted laser signals.

In one aspect of this technology a dynamically steerable laser rangefinder can begin a scan of a FOV at a low elevation angle (e.g. 20degrees below the horizon) and below the eye-level of most people. Thedynamically steered laser range finder can slowly increase the elevationangle while scanning the azimuthal range (e.g. sweeping side to sidewhile slowly rising). At a point in the scan a sensor data processor canidentify a region of the FOV estimated to contain a person based on theinitial data form the scan (e.g. seeing a person's legs and torso basedon process initial data). The sensor data processor can define a keepoutregion corresponding to an estimate location of the head of a person.Circuitry (e.g. the data processor or laser steering parameter generatoror a laser detector operably coupled to a remote processor) can generateinstructions, based at least in part on the keepout region location andthereby dynamically steer the steerable laser based on the instructionsto avoid transmitting laser pulses at one or more identified people'sheads. In one alternative embodiment one or more sensor technologies(e.g. a camera, ultrasound or radar) can be used to estimate thepresence and location of a person in the FOV of the LIDAR and theestimated location can be used to generate the keepout region. Lasersteering parameters (e.g. instructions) can be generated or modifiedbased on the location of the keepout region. In another alternativeembodiment the LIDAR can estimate the location of a person based on aprevious scan. In another embodiment a location in the FOV can beidentified that could contain a human head or eyes (e.g. behind a carwindshield or at eye-level). In one embodiment one or more processorscan calculate one or more keepout regions based on indications ofregions likely to contain peoples head and eyes.

This technique can be implemented to achieve the following exemplaryadvantages: Laser exposure to the head and eye region can be reduced.Laser intensity can be increased in regions determined to be free ofpeople or animals. The laser can be dynamically steered to provide asafer environment.

FIG. 35 illustrates two different non-uniform density laser pulsepatterns 3505 and 3510. Non-uniform density pulse pattern 3505 containsseveral laser pulses (e.g. 150 a) that are aimed at the head of person160. Non-uniform density pulse pattern 3510 is based in part on keepoutregion 3520. Laser pulses in non-uniform pulse density pattern 3510 aregenerated to avoid directed pulses into keepout region 3520. For thepurpose of this disclosure a keepout region is a portion of the FOV of alaser. The keepout region can be used to generate instructions to thesteerable laser to avoid generating pulses within a region of the FOVbased on the keepout region. The keepout region can be defined in termsof boundary coordinates (e.g. a point in the FOV defining corner 3530,such as X=10, Y=20). The keepout region can be expressed as a set ofangular ranges in the FOV (e.g. +15 degree to +10 degrees in theazimuthal plane and +0 to +5 degrees in the elevation plane, therebydefining a square shape region). The keepout region can be a shape froma predefined at of shapes (e.g. a head shaped keepout region). Thesepredefined shapes can be scales (e.g. made bigger), and positioned inthe FOV based on sensor data indicating the presence of people oranimals in the FOV.

Keepout region 3520 can be sized and positioned based on the currentestimate location of a person's head or an expected future location oftheir head. For example, Sensor data processor 3375 in FIG. 33 canreceive data from several camera images and identify a person moving inthe foreground of the image. Sensor data processor 3375 in FIG. 33 canestimate the trajectory (e.g. walking speed) of the person and generatea keepout region designed to encompass the region of the FOV likely tocontain the persons head at some future time. Sensor data processor 3375in FIG. 33 can transmit the keepout region to a laser steering parametergenerator/modifier 3110 that can convert the keepout region into a setof instructions operable to dynamically steer steerable laser 3015. Theinstructions can cause the steerable laser to avoid the keepout regionor a similar shaped region based on the keepout region and thereby avoidtransmitting the laser at the persons head. In one embodiment sensordata processor 3375 in FIG. 33 can process sensor data and access a listof laser instructions and directly modify the laser instructions, basedon a computed set of criteria. In this way the keepout region need notbe explicitly defined during instruction generation but can beimplicitly defined by the set of criteria used to generate instructionsthat in turn generate a laser scan patterns with a keepout region. Forexample, data processor 3375 in FIG. 33 can process sensor data from acamera and thereby instruct a laser steering parameter generator toremove a list of points from the non-uniform density laser pulse pattern3510 to generate pattern 3520 (e.g. define zero laser energy or instructthe laser to not power, or mask a laser amplifier at particularlocations in the FOV). The resulting laser steering parameters (e.g.instructions) can generate a non-uniform density laser pulse pattern(e.g. 3510) that avoids a particular region (i.e. an implicitly definedkeepout region), even though the bounds of the keepout region are notexplicitly identified by sensor data processor 3375 in FIG. 33. Inanother alternative embodiment the proposed method for controlling asteerable laser can be used to define keepout regions based on a widevariety of identified objects (e.g. people, animals, vehiclewindshields, the windows of houses).

FIG. 36A illustrates a method 3600 operable to steer a laser based on anobject to be avoided with laser pulses. At block 3610 method 3600begins. At block 3620 sensor data indicative of or more aspects of anenvironment in a field of view of a steerable laser with dynamicsteering capability is obtained. At block 3630 a location of at leastone portion of an object is estimated based on the sensor data. At block3640 a keepout region for the steerable laser is determined based on theestimated location of the at least one portion of the object. At block3650 a set of instructions is generated, based on the keepout region. Atblock 3655 the steerable laser is steered using the set of instructions.At block 3660 method 3600 ends.

FIG. 36B illustrates a method 3601 operable to steer a laser based on anobject to be avoided. At block 3610 method 3600 begins. At block 3620sensor data indicative of or more aspects of an environment in a fieldof view of a steerable laser with dynamic steering capability isobtained. At block 3630 a location of at least one portion of an objectis estimated based on the sensor data. At block 3635 an objectclassification for the object is determined based on the sensor data.Exemplary classifications can include a person, an animal, a vehicle, ora building. At block 3645 a keepout region for the steerable laser isdetermined based on the estimated location of the at least one portionof the object and based on the object classification. For example, akeepout region can be tailored to an expected shape for a person or avehicle. In a related embodiment classification can be an environmentclassification such as an urban environment or a rural environment. Forexample, an environmental classification can be urban setting and thesensor data can indicate a heading or direction of travel for a vehicle.The combination of the urban classification and the heading of travelcan be used to generate a keepout region in a portion of the FOVexpected to contain pedestrians on footpaths. At block 3650 a set ofinstructions is generated, based on the keepout region. At block 3655the steerable laser is steered using the set of instructions. At block3660 method 3601 ends. In one example the keepout region is based on atrajectory of a moving object to incorporate a future or anticipatedlocation of an object. In another example a keepout region is calculatedbased on the speed of a detected object.

FIG. 36C illustrates a method 3602 operable to steer a laser based on anobject to be avoided. At block 3610 method 3600 begins. At block 3620sensor data indicative of one or more aspects of an environment in afield of view of a steerable laser with dynamic steering capability isobtained. At block 3633 a location of an object is estimated based onthe sensor data. At block 3643 the sensor data is processed to identifya location of an object in the field of view and to generate a set oflaser steering parameters based at least in part on the identifiedlocation of the object. At block 3653 the steerable laser is steeredusing the set of laser steering parameters to generate a set of laserpulses with directions in the field of view that avoid the keepoutregion. At block 3660 method 3602 ends. In a related embodiment sensordata (e.g. laser range measurements) can indicate a distance to anobject. Method 3600, 3601 or 3602 can further comprise the step ofprocessing the sensor data to determine the distance to the object inthe field of view; and generating the set of laser steering parameters,based at least in part on the distance to the object, such that the setof laser steering parameters function to define a size of the keepoutregion based at least in part on the distance to the object. Forexample, if the sensor data indicates a person at 20 m from the LIDARthe keepout region can be defined by an elevation and azimuthal angularrange of 5 degrees and 10 degrees respectively, centered at the locationof the person in the FOV. If the person later moves to a distance of 10m from the LIDAR the keepout region can be increased to 10 degrees and25 degrees in the elevation and azimuthal directions respectively.

FIG. 37 illustrates a keepout mask circuit operable to receive signalsbased on one or more keepout areas and to provide a masked input signalto a laser transmitter. In a typical rotating LIDAR a laser generationsignal 3710 is supplied to a laser transmitter/generator 3015. Lasergeneration signal 3710 can function to cause laser transmitter 3015 togenerate one or more laser pulses 3705. Laser generation signal 3710 canbe a low power signal (e.g. 5V) generated by closing a switch used toturn the laser transmitter ON/OFF. A low power laser generation signalcan be used to as an input to an amplifier at the laser transmitter3015, thereby generating a more powerful electrical signal operable togenerate laser pulses. Laser pulses 3705 can travel into a rotatingLIDAR head 3720, including optics 3730 (e.g. a mirror, reflector orprism). The angular position of the rotating LIDAR head 3720 can bemeasured by position sensor 3740. In the embodiment of FIG. 37 a keepoutmask circuit 3760 can function to dynamically mask the laser generationsignal based on a mask signal and thereby generate keepout regions inthe transmitted FOV of the LIDAR. Position sensor 3740 can supply anindication of the LIDAR head position to a keepout region memory. Thekeepout region memory can be part of a processor that can use the LIDARhead position to generate a mask signal 3755. In one embodiment eachposition sensor value can have a corresponding mask signal value (e.g.“0” for masked and “1” for unmasked).

The keepout region memory can store the mask signal values correspondingto some or all possible position sensor values. Keepout region memory3750 can be updated by laser steering parameter generator/modifier 3110or sensor data processor 3375 in FIG. 33. Keepout mask circuit 3760 canreceive keepout mask signals 3755 and laser generation signals 3710 andcan generate masked laser generation signals 3765. Masked lasergeneration signals 3765 can cause laser transmitter 3015 to transmitlaser pulses when the position sensor indicates that LIDAR head 3720 ispointed outside certain keepout regions and conversely can stop laserpulses when the LIDAR head is pointing into keepout regions. System 3700is particularly useful in situations where the distribution of laserpulses into the FOV is not dynamically controllable, such as the casewith a rotating LIDAR head. Instead the LIDAR head position is sensedand the laser transmitter is dynamically gated by keepout mask circuit3760. In a related embodiment a solid state LIDAR can analyze a scene,identify a person in the scene and generate a complex shaped 2-D keepoutregion. For example, in complex 2-D shaped region in a FOV designed toprovide a safety margin around a person walking in front of a vehicle, asolid state LIDAR can provide keepout mask signals to a laser generatorduring corresponding times in a scan of the FOV.

LIDAR with Direction Feedback

Turning to FIG. 40 a direction-detecting solid-state LIDAR 4000 cancomprise an optical phased array (OPA) 4005, and direction feedbacksubassembly 4010 in a common LIDAR enclosure 4002. In most situations alaser detector in a LIDAR receives laser reflections from objectsoutside the LIDAR enclosure 4002. The direction feedback subassembly4010 can function to directly detect the outgoing laser beam in one ormore calibration directions. In several embodiments the directionfeedback subassembly 4010 can include control circuitry to adjust theOPA and thereby provide a self-calibrating feedback-based solid-stateLIDAR. The direction feedback subassembly circuitry can directly detectlaser intensity in the one or more calibration directions and adjust theOPA to change the output laser direction. In one aspect the feedbackcircuitry can adjust the electrical signals to the phase shifters in theOPA to compensate for environmental factors such as temperature orhumidity as well as manufacturing variations. In another aspect theelectronic circuitry can function to confirm that the OPA and the laserdetector in the circuitry are capable of both transmitting a laser beamin the one or more calibration directions and receiving the laser beam.

Turning in detail to FIG. 40, OPA 4005 can comprise a laser generator4015 such as a laser diode and a laser splitter 4020 operable to dividea laser beam into a plurality of sub-beams. A plurality of phaseshifters 4025 (e.g. a liquid crystal, thermal or phase shifter or Indiumphosphide phase shifter) can delay each of the sub-beams by varyingamounts. The resultant phase shifted sub-beams can be combined through aseries of waveguides or antennas 4030 to produce a directed laser beamwith a primary far field lobe 4040. In one aspect a direction feedbacksubassembly 4010 can comprise a reflector 4050 to reflect a laser beamtransmitted by the OPA 4005 in a particular calibration direction 4045.Alternatively, a plurality of reflectors 4060 can reflect a laser beamin a plurality of calibration directions. Recent advancements inreflective liquid crystal materials have made electronically switchablemirrors possible (e.g. the e-Transflector product line available fromKent Optoelectronics of Hopewell Junction, N.Y.). In one aspect onereflector 4050 or reflector array 4060 can be electronically switchablemirrors. These electronically switchable mirrors can function to reflectthe laser beam towards reflector 4065 when switches ON and function tobe transparent to a laser beam (e.g. in direction 4045), when turnedOFF, thereby passing a laser beam beyond the enclosure 4002. In thisway, an embodiment of direction feedback subassembly 4010 withelectronically switchable mirrors can function to measure thedirectional accuracy of OPA in the reflective state (i.e. the ON state)of the switchable mirrors 4050 or 4060. Laser detector 4065 can be adedicated photodiode or can be at least a part of the laser detector forthe LIDAR 4000. Laser detector 4065 can receive a reflected laser beamand generate a reflection signal 4080 indicating the intensity of thelaser reflection. The intensity of the laser reflection and thereflection signals can be compared with an expected value by controlcircuitry 4070. Alternative control circuitry 4070 can generate aperturbation signal 4085 to the phase shifters 4025 that cause the phaseshifters to vary the main lobe direction 4040 and thereby identify anoffset adjustment signal 4072 that causes the maximum intensity in thecalibration direction 4045, thereby indicating that the main lobe 4040is pointed in the calibration direction 4045. In a related embodimentlaser detector 4065 can detect the laser intensity in the calibrationdirection and similar directions directly. The offset adjustment signal4072 can function to adjust the OPA to account for variations due totemperature or aging of the LIDAR.

Similarly, control circuitry can function to adjust the OPA to providemaximal intensity in the calibration direction when a correspondinginput calibration signal 4075 commands the OPA to point in thecalibration direction 4045. In one embodiment control circuit 4070 canassert a malfunction indicator signal 4085 (e.g. a 0-12V value) if, inresponse to the input calibration signal 4075 the OPA does orient thelaser beam in the calibration direction 4045. The malfunction indicationsignal 4085 can connect the control circuit or the laser detector 4065to a malfunction indicator pin 4090 on the enclosure 4002 of LIDAR 4000.In one embodiment both the input calibration signals 4075 and the offsetadjustment signal can be generated by the control circuitry 4070.

FIG. 41 illustrates a solid state LIDAR 4100 inside an enclosure 4102.OPA 4110 can generate a near-field beam pattern and a primary far-fieldlobe 4115 with a beam-width 4117. LIDAR 4100 can further comprise aselective light modulator (SLM) 4120 such as an LCD array that canselectively make pixels such as 4130 and 4125 transparent and opaque.SLM 4120 can function to collimate or narrow the beam-width of far-fieldlobe 4115, thereby generating a collimated beam 4140. Collimated laserbeam 4140 can have a smaller spot size than the uncollimated far-fieldlobe 4117 and can hence reflect from a distinct region of reflectiontarget 4150. Laser detector 4160 can receive reflected laser pulse 4155and generate reflected signal 4165. In one aspect control circuitry 4170can control OPA 4110 to adjust the far-field lobe direction to generatethe maximum laser intensity for a particular aperture (e.g. subset oftransparent pixels such as 4130 in the SLM). In another aspect theaperture in the SLM can be varied for a given OPA setting to achieveenhanced laser resolution for selectively transmitting subsets of thefull far-field beam-width. For example, an OPA may be capable ofgenerating 10000 distinct laser beam directions. The SLM can comprise400×600 LCD pixels and can thereby provide 240000 distinct collimatedlaser beams 4140. In one embodiment the OPA is adjusted to particularlaser direction and a sequence of SLM aperture shapes transmit subsetsof the far-field laser cross-section thereby enhancing the laserresolution.

Planning a Laser Ranging Scan with Smart Test Vectors

Laser ranging systems generate a limited number of laser pulses persecond. Often many pulses are directed at mundane parts of the FOV (e.g.an empty section of roadway) while at the same time another portion ofthe FOV is undergoing an important change. The methodical scan patternperformed by many LIDAR is a disadvantage considering that interesting,important or highly indicative parts of the FOV are often non-uniformlydistributed and can be well known. In other instances an interestingobject in the FOV (e.g. a truck) can be acting in a mundane, predictedor unchanged manner (e.g. constant relative location). A dynamicallysteered laser ranging system (e.g. a solid state LIDAR) may identify theinteresting object and repeatedly devote a disproportionate number ofthe laser scan locations to the interesting object (e.g. a higherdensity of laser ranging locations) despite the object behaving in alargely unchanged manner. For example, continually scanning ten vehiclesin a FOV with a high density of measurement locations can consumer alarge portion of the available scan time. In one aspect it is better toidentify a few locations representative of the present locations of eachthe ten vehicles and apply simple test vectors or rules to identify if adense scan of each vehicle is necessary. Several embodiment of thedisclosed method provide for planning and executing a non-uniformlyspaced set of laser ranging measurements (e.g. a main scan of the FOV)based on first testing a set of previously identified importantlocations. Properties of ranging data from a set of test locations canbe assessed early and in some cases often during a scan of the field ofview.

Several embodiments of the present disclosure can be used tocharacterize the objects in the FOV and thereby generate a set of rules(e.g. test vectors operable to indicate the presence of an object edgein a small test region), evaluate the rules at some later time andthereby plan a larger laser ranging scan based on the results. Inseveral embodiments of the present technology laser reflections from asmall set of important (i.e. highly indicative) test locations aregathered early in a scan of a FOV and evaluated to determine parameters(e.g. patterns and areas of high pulse density) for a larger scan of theFOV.

Four aspects of several embodiments are: Firstly to identify a smalltest subset of the FOV (e.g. a set of 100 test locations) whereinreflected laser pulses are highly indicative (i.e. representative) ofthe location of important objects, secondly to laser scan the small testsubset of the FOV early in a scan. Thirdly a set of rules (e.g. testvectors or criteria) can be evaluated using the reflections from the settest locations and fourthly a larger main scan of a larger portion ofthe FOV can be planned based on the results of the set of rules.

A key beneficial aspect of several embodiments is to use a steerablelaser assembly to dynamically scan the set of test locations in rapidsuccession, thereby gathering the test data early in a scan and planningthe remainder of the scan accordingly. Similarly, a steerable laserassembly provides the capability to use learning from the test locationsto generate complex shaped regions of variable laser pulse density basedon the test data. In contrast a traditional non-dynamically steerablelaser range finder (e.g. HDL-64E from Velodyne LIDARs of Morgan Hill,Calif.) performs a predetermined scan pattern. The non-dynamic scanpattern is not adjustable to favor important locations associated withtest vectors (e.g. the edges of a car or the placement of a pedestriansarms and feet) over mundane laser scan locations (e.g. the ground or theside of buildings). However, a dynamically steered laser system canfirstly scan at a set of test locations associated with test vectors andsubsequently plan a scan of the field of view in a non-uniform mannerbased on the results.

In one embodiment a laser ranging system comprises a computer processorand a steerable laser assembly that can receive laser steeringparameters from the computer processor and steer one or more laser beamsaccordingly. The laser ranging system generates a plurality of testvectors, based on a previous laser ranging scan. Each test vector is acriterion that can be satisfied by aspects of laser reflections (e.g.the time of flight) from one or more locations in a set of testlocations. For example, a test vector may be a criterion that issatisfied if the edge of an object (e.g. a time of flight dislocation)is located between two locations in the set of test locations. Inanother example a test vector can be formulated for a small test region(e.g. 39-41 degrees azimuth and 9-11 degrees in elevation), based inpart on the presence of the boundary of an object in the test region atsome earlier time. The test vector can be a criterion that is satisfiedif reflections from at least some of the test locations in the testregion indicate reflection from the background (i.e. beyond an object)while at least one reflection from a test location in the test regionindicates reflection from the object.

The laser ranging system first steers one or more lasers with thesteerable laser assembly to generate laser pulses at the set of testlocations and evaluates the test vectors based on aspects of thereflected laser pulses, thereby generate a set of results (e.g. TRUE orFALSE for each test vector). The laser ranging system then plans alarger scan of the FOV (e.g. a scan with 100,000 points) based on theset of results gathered by evaluating the set of test vectors. Forexample, the computer processor in the laser ranging system can identifya failed test vector from the set of results (e.g. a car tire that haschanged position and no longer satisfies a test vector) and plan thelarger scan to include a dense scan region operable to search for afeature (e.g. the new position of the car tire) in the FOV.

In several embodiments a set of test locations and an associated set ofrules (e.g. test vectors) can be generated from laser ranging dataprovided by previous scans of the FOV. In other embodiments testlocations can be selected based in part on other sensors such ascameras. A new laser scan of the FOV can be planned in advance, by firstscanning the set of test locations and evaluating the set of rules (e.g.test vectors). In several embodiments, at the beginning of a scan adynamically steerable laser assembly (e.g. based on an optical phasedarray or mechanical laser beam steering optics) can steer a laser beamaccording to a first set of laser steering parameters to generate testdata at a set of test locations. A set of predetermined test vectors canbe evaluated and thereby generate a set of test results indicating thateach test vector is either TRUE (i.e. the test vector is satisfied) orFALSE (the test vector is unsatisfied).

The test vectors can identify aspects of a laser ranging point cloudindicative of position or orientation of various objects in the field ofview at some previous time (e.g. during a previous laser scan). Forexample, a laser ranging system on an autonomous vehicle can identify aplurality of edges and vertices associated with a nearby car. Testvectors can be generated based on the location of edges and vertices onthe nearby car. Similarly a test vector can be generated based on theplacement of the edge of a tire on the nearby car relative to a lanemarker (e.g. a lane divider stripe).

In one exemplary embodiment, upon identify that a test vector is failed(e.g. evaluates to FALSE) a set of laser steering parameters can begenerated to perform a laser scan in a search region of the FOV andthereby generate a replacement or updated test vector based on the laserranging scan. The laser scan of the search region can have non-uniformspacing (e.g. decreased angular separation in one or more directions inthe FOV, thereby producing a higher density of measurement directions)relative to other areas of the FOV. For example, if a laser rangingsystem identifies that an edge associated with the side of a nearby caris no longer encompassed by one or more locations in the set of testlocations, the system can identify a search region and perform a denselaser scan of the search region to reacquire the edge location andgenerate an updated test vector.

In another embodiment of a scan planning method, a scan of a FOV canbegin with a first set of laser steering parameters that function tomove a steerable laser assembly in the FOV and thereby generate a set oftest data at a set of test locations. The set of test locations can beuniformly or non-uniformly spaced in the FOV. This set of test locationsfunctions to seed a larger main scan of the FOV. A set of rules isselected and functions as a transfer function between the test data anda second set of laser steering parameters operable to dynamically steera laser beam with the steerable laser assembly to perform the main scan.In one simple example the set of test locations can be 100 locationsarranged in a 10×10 grid in the field of view. The main scan can beplanned such that test locations that indicate a large change in rangerelative to some previous measurement, or relative to neighboring testlocations cause a higher density of points in the corresponding locationduring the main scan.

In another example a computer implemented method can begin by obtaininga set of tests, each operable to be evaluated using at least some of aset of test data indicating one or more aspects of laser reflectionsfrom a set of test locations within a field of view. A laser rangefinder can then generate one or more test laser pulses and generate theset of test data by measuring the one or more aspect of laserreflections from the one or more laser pulses. The computer implementedmethod can then generate a scan set of laser steering parameters, basedat least in part on evaluating each of the set of tests using at leastsome of the set of test data. The method can then steer at least onelaser beam using a steerable laser assembly in the laser range finder,based on the scan set of laser steering parameters, and thereby generatea scan set of laser pulses at a set of scan locations in the field ofview.

The techniques described in this specification can be implemented toachieve the following exemplary advantages: The performance of a laserranging system can be improved by planning a non-uniformly distributedscan of a field of view based on a small set of up-to-date testlocations. The non-uniform distribution of scan locations can be used tosearch for new objects, and increase resolution of objects exhibitingchanges.

The performance of a laser ranging system can be improved by identifyingand maintaining an up-to-date list of important test locations. Acorresponding set of rules can be maintained, thereby providing a rapidbasis for comparison of new test data with previous rangingmeasurements. The disclosed scan planning method also provides for usingother sensing technologies (e.g. cameras and ultrasound) to identifyimportant locations in the FOV that warrant characterization. Hence theproposed scan planning method provides for distilling the complexbehaviors of objects in the FOV into a small set of test locations andrules that provide a rapid basis for planning a non-uniform laserranging scan.

Embodiments of the scan planning method can improved the efficiency ofLIDAR systems. Current laser ranging systems spend considerableresources methodically scanning mundane locations (e.g. open road).Existing dynamically steered laser ranging systems can continuouslyidentify an object and devote considerable time and laser resources torepeatedly scanning an unchanging object. Embodiments of the disclosedtechnology rapidly tests a small set of test locations to determine ifthe object or region of interest warrants a dense scan as part ofplanning a subsequent main scan.

Embodiments of the scan planning method enable faster planning of alaser ranging scan by generating the test vectors prior to gathering thetest data from the set of test locations. For example, multiple testvectors can be established along a common edge of an object and therebyprovide a basis for rapid determination of direction changes.

The disclosed techniques can improve the reaction time of system (e.g.braking or steering) that rely on the laser ranging system. Generatingthe set of test locations and set of rules before beginning a scanprovides upfront knowledge of where the most important locations in theFOV should be. Several embodiments provide for scanning these testlocations first. For example, a mechanically scanned LIDAR rotating at10 Hz scans the FOV every 100 ms. Hence in a worst-case-scenario wherethe set of test locations for the test vectors occur at the end themechanical LIDAR scan, the time required to evaluate the set of testvectors includes a 100 ms data acquisition portion. In contrast, thedisclosed technology can provide for scanning the set of test locationsfirst thereby reducing the time to evaluate the test vectors (e.g. reactto a rapid change in direction by another car) by almost 100 ms. Forcomparison, the average visual reaction time for humans can be 250 ms.

The disclosed system can scan the points associated with the testvectors multiple times throughout a scan of the FOV and adjust the lasersteering parameters according to the results. Unlike a system thatidentifies objects of interest and scans those objects at a higherfrequency the disclosed technology provides for performing a morecomputationally efficient evaluation of a smaller set of test vectorsmultiple time throughout the course of a scan of the FOV. For example,an exemplary laser ranging system can scan 200,000 in the course of a100 ms scan of the 360 degree FOV. If the laser ranging systemidentifies a fast moving vehicle and attempts to scan the vehicle every10 ms with 10,000 points it must devote half of the total scan points tothe task of scanning the vehicle. The disclosed system instead providesfor scanning the set of test locations every 10 ms and only scanning thevehicle when test vectors indication deviation from a position or path.

In another advantage a plurality of test vectors can be associated withan object classification. For example, an autonomous vehicle canidentify a specific type of nearby vehicle (e.g. a school-bus) and canprovide a plurality of test vectors to an associated laser rangingsystem.

A considerable advantage of embodiments of the scan planning methods isto reduce the effect of motion artifacts for moving objects. Onechallenge with scanning a LIDAR in a uniform, or non-dynamic manner isthat various parts of a moving object are scanned at various timesthroughout the scan. Consider that a left to right and top to bottomuniform scan of a FOV over 100 ms can scan the roof of a vehicle firstand the tires of the vehicle last. The vehicle can have movedsignificantly in the course of the scan (e.g. at 30 mph the vehiclemoves 1.3 m in the course of the scan). The disclosed technologyprovides for using a set of test vectors to identify a moving object andthereby dynamically steer a laser to scan all points on the movingobject in a short window of time (e.g. consecutively). This provides forreducing motion artifacts.

In another advantage the disclosed technology provides for prioritizingthe order in which portions of the FOV are scan based on those areasdemonstrating the most change. For example, a laser range finding systemmay have 100 test vectors, 10 of which are unsatisfied, with 9unsatisfied test vectors being associated with a first portion of theFOV and 1 unsatisfied test vector being associated with a second portionof the FOV. The disclosed technology enables the generation of lasersteering parameters that prioritize the first portion of the FOV (i.e.an area more in need of updating) operable to perform a non-uniformlaser pulse density scan within the first portion followed by the secondportion of the FOV.

The disclosed techniques can improve the cost effectiveness of a laserrange finder. A lower price laser range finder may have fewer lasers ora slower laser pulse rate. The disclosed techniques enable a laser rangefinder with a smaller total number of laser pulses per second todistribute those laser pulses in a dynamic and intelligently selectedmanner.

FIG. 42 illustrates a laser range finder 110 comprising a dynamicallysteerable laser assembly 120. Dynamically steerable laser assembly 120is operable to receive instructions based on laser steering parametersand thereby move a laser beam in a complex non-linear pattern in a fieldof view FOV 4230. In several applications (e.g. autonomous vehicles) theobjective of laser range finder 110 can be to track the location ofinteresting objects (e.g. elephant 4240). Laser range finder 110 can usedynamic laser steering to perform laser ranging in a complex-shaped scanregion (e.g. 4250) associated with the elephant. In this way the densityof laser scan locations (e.g. the number per unit angle of the field ofview, such as 4 scan locations per radian) can be increased for objectsof interest such as elephant 4240 and decreased for mundane regions suchas the ground surrounding the elephant. One method of operating laserrange finder 110 can be to increase the density of laser pulses based onregions of the FOV exhibiting distinct boundaries (e.g. elephant 4240)relative to the background. One disadvantage with this approach is thatelephant 4240 can remain stationary in the FOV and a large number oflaser ranging measurements can be consumed in the process of repeatedlyscanning the region 4250 with an increased density of rangingmeasurements.

Test Locations

In several applications, the laser range finder 110 (e.g. guiding anrobot) is more interested in when the elephant changes position, withthe lowest possible latency, than confirming all points on the elephantin consecutive scans. This, “low-latency movement sensing” objective canbe performed more efficiently by identifying a small set of test pointswith high predictive power regarding the location or direction of theelephant. A primary aspect of several embodiment of this disclosure isto identify an up-to-date set of highly predictive test locations. A setof test locations (e.g. 4270 a close to the tip of the elephants trunk)can act like a fingerprint, thereby providing reflection data that ishighly indicative (e.g. has a high correlation factor) of a much largerset of points (e.g. on the body of the elephant). Test locations in theFOV can be scanned and ranging data gathered before performing a mainscan of the FOV. In a similar manner to how a fingerprint is identifiedby fulfilling a set of characteristic criteria, a set of rulescorresponding to the set of test locations can be obtained. In somecases the set of rules can be obtained prior to gathering the set oftest points. The set of rules can be evaluated based on test data fromthe set of test locations to generate a set of results. The set ofresults can be used to plan a larger scan (e.g. a scan of the remainderof the FOV or a portion of the FOV with a higher density of laserpulses).

In one example, steerable laser assembly 120 can first be steeredaccording to a first set of laser steering parameters to generate a setof test laser pulses at a set of test locations (e.g. 4270 a and 4270 b)within a set of test regions 4260 a and 4260 b. Test data can begathered from aspects of reflections at the set of test locations and aset of rules can be applied to the test data. The test results canindicate that elephant 4240 has not moved since a previous scan andtherefore a main scan can be planned in a manner that does not generatea high density of measurements in a scan region associated with theelephant. At a later time, the set of test locations can be remeasuredand updated test data from test locations 4270 a and 4270 b can indicatethat the elephant has moved and a second set of laser steeringparameters can be generated perform a search for the elephant (e.g. highdensity in region 4250).

Consider that exemplary LIDAR HD-64E from Velodyne LIDARs of Morgan HillCalif. can generate 2.2 million laser pulses per second. A single scan(e.g. a main scan) of the FOV can take 100 milliseconds and includes220,000 locations. While HDL-64E is not dynamically steerable, a similarLIDAR with a dynamic steering capability and utilizing an embodiment ofthe present scan planning method can: first scan a set of 1000 importanttest locations in less than 0.5 milliseconds and then plan and performthe remainder of the scan of the FOV in more intelligent, non-uniformmanner.

In the related field of image process (e.g. facial recognition) featurescan be derived from an image in an intelligent manner such that theyprovide correlation or predictive power over larger portions of thedata. Facial recognition often selects features to provide maximumrelevance and lowest redundancy in the task of differentiating faces. Inthe case of the elephant it may not be important that a featureidentifies the object as an elephant or even differentiates the elephantfrom other elephants. Instead for the task of range finding; aneffective feature can have high correlation and specificity to changesin range for a larger, well-defined portion of the FOV. A feature can bea pattern of ranging data (e.g. the pattern of ranging data associatedwith the trunk of the elephant). One or more test vectors can beassociated with the feature. Each test vector can function as a test ofwhether the feature is present within a test region. For example, afterperforming a dense scan of the elephant, laser range finder 110 canidentify features (e.g. the tip of the trunk and tail). At the beginningof a subsequent scan system 110 can first scan within the identifiedsmall test regions 4260 a and 4260 b and verify the location of theelephant by processing the test data from the test regions.

For some time the elephant can satisfy the test vectors associated withthe features and test regions. At a later time the features may movelocation in the FOV and fail to satisfy one or more test vectors. One ormore test regions can be updated as the elephant moves. A feature canundergo changes (e.g. the perspective of the feature may change when theelephant turns towards the laser ranging system). In this case aspectsof the feature and aspects of the associated test vectors can beupdated.

Test Regions/Test Locations

Turning in-depth to FIG. 42 an intelligent choice of test regions (e.g.4260 a) or test locations (e.g. 4270 a) can be a first step in planninga larger scan. In some embodiments test locations can be uniformlydistributed throughout some or all of the FOV 4230. In other embodimentstest regions or test locations can be non-uniformly distributed and canbenefit from dynamic steering to reach the test locations without havingto perform many intervening measurements outside the set of testlocations. In some embodiments a set of test locations can be specifiedand provided to the steerable laser assembly. In other embodiments thesteerable laser assembly sweeps a laser along a path and generatespulses continuously. Hence, with a continuously pulsing laser generatorand a sweeping laser positioner it may be difficult or impractical tospecify an exact location for the test pulses. For this reason it can bemore convenient to specify test region in which the laser beam should besteered and thereby generate test laser pulses at a set of testlocations (e.g. 4270 a and 4270 b). In this case the exact set of testlocations can become known upon dynamically steering a laser beam in theset of test regions.

Effective test regions (e.g. 4260 a) or test locations (e.g. 4270 a)provide ranging data (e.g. distance and reflectivity) that is highlypredictive of a larger portion of the FOV (e.g. an object). An objectiveof several embodiments is to find these locations with high correlationto objects in the FOV. Test regions and test locations can be selectedusing a variety of techniques, such as boundary detection, imageprocessing or feature recognition. Boundary detection is one simple wayto select test regions and test locations based on sensing objectboundaries. The boundary of elephant 4240 can be recognized from cameraimagery and test region 4260 c can be placed on the boundary of theelephants head. Feature recognition is often used in machine learning toclassify objects in images. In image processing and machine learningfeatures are often predicted to provide the highest specificity (e.g. todifferentiate the elephant form a horse). Test regions can be selectedbased on identified features (e.g. the elephant's trunk and tail). Testregions can be selected based on supervised machine learning, where forexample, the laser range finder 110 is trained to recognize particularfeatures (e.g. the corner of a car bumper or the trunk of the elephant)and place test regions accordingly. Interestingly, the laser rangefinder 110 can also use unsupervised learning to generate features andlocate test regions. For example, a reward function can be establishedto identify a measure of how well a test region (or a set of testlocations in a test region) predicts the location (i.e. range) anddirection of an object (i.e. the direction can be estimated from achange in the object cross-section presented within the FOV). Over thecourse of several seconds the laser range finder 110 can identify testregions that maximize the reward function for a variety of objectsundergoing changes. For example, test region 4260 d in the center of theelephant may have high correlation with changes in the range of theelephant but low correlation to small movements of the elephant fromleft to right. Hence region 4260 d may be a poor choice of test region.Test regions 4260 a and 4260 b may contain defining features (e.g. thetrunk and tail) but movement of the trunk and tail may cause changes inrange that do not correlate with changes in the overall position of theelephant. Test region 4260 c may be a good choice of test region (e.g.have a high reward value) because it correlates with changes in rangeand lateral (left, right) motion. Test region 4260 c is also places onthe elephants head and can thereby provide early indication that thehead has moved and a direction change may ensue. The best way to selecttest region 4260 c may be through unsupervised machine learning of thosepoints in the FOV that have the best correlation to changes in largerregions. In one example laser range finder 110 can identify acorrelation between test location 4260 c and scan region 4250 usingunsupervised learning and can subsequently perform a scan of the FOVwhere the density in scan region 4250 is based at least in part on theresult of a rule applied to test region 4260 c.

Another approach to selecting test locations or test regions is toutilize historical learning. For example, laser range finder system 110can use previous similar instances (e.g. when a computer vision systemreported that an elephant was in the FOV) to select and position testlocations. Yet another approach is to select test locations or testregions based on the geographic location of laser range finder system110. For example, a GPS system can report to laser range finder 110 thatit is located in the garage of an owner's home. This information can beused to select test regions corresponding to historical features (e.g.bicycles, workbenches, and the boundary of the garage door). In this waylaser range finder 110 can develop a set of test locations andassociated rules with common geographic locations (e.g. GPS locations orWi-Fi signals indicating locations). In another example the geographiclocation can cause laser range finder 110 to select a classification forthe location (e.g. urban) and thereby select a set of test regions (e.g.at a location typically associated with a pedestrian waiting to cross acrosswalk). The set of test regions (e.g. 4260 a and 4260 b) and testlocations (e.g. 4270 a) can be conveyed to the steerable laser assembly120 using a first set of laser steering parameters. Other scenarios thatcan be used to generate test locations or test regions could include; anobstacle in a blindspot, a lane departure of another vehicle, a newvehicle in the FOV, sudden changes in traffic flow, approaching vehiclesat an intersection, approaching obstacles when backing up, debris on theroad, hazardous road conditions including potholes, cracks or bumps orhazardous weather conditions.

FIG. 43 illustrates several exemplary sets of data generated or used byan exemplary embodiment of a scan planning method based on test vectors.FIG. 44 illustrates several vehicles in the FOV of a laser range finder110 that is performing an exemplary embodiment of a scan planningmethod. FIG. 43 illustrates an exemplary first set of laser steeringparameters 4310. The first set of laser steering parameters 4310 canfunction to instruct steerable laser assembly 120 to dynamically steerone or more laser beams and thereby perform ranging at a set of testlocations 4320 or within a set of test regions. A laser steeringparameter (e.g. 4316) in the first set of laser steering parameters 4310can specify one or more test locations (e.g. X1, X2). Other lasersteering parameters (e.g. 4317) can specify the bounds of a test regionand thereby generate one or more points within the test region (e.g.location X11 within the set of test locations 4320). The first set oflaser steering parameters 4310 can include a start location 602 in FIG.6A, a region width 604, a region height 606, scan path waypoints e.g.612, laser scan speed e.g. 614, laser pulse size e.g. 616, and a numberof pulses 618 in FIG. 6A. The first set of laser steering parameters canbe generated by a computer processor such as laser steering parametergenerator 410 in FIG. 4A. Alternatively the first set of laser steeringparameters (e.g. 4310) can be stored in a memory within the laser rangefinder (e.g. a non-volatile memory containing laser steering parametersoperable to generate 100 test locations in uniform 10×10 grid). Theoverall function of the first set of laser steering parameters can be togenerate ranging measurements (e.g. time of flight and intensity ofreflected pulses) at a set of test locations 4320. In order to rapidlygather measurements from the set of test locations, the first set oflaser steering parameters can steer steerable laser assembly 120 in FIG.42 in a dynamic and non-uniform manner. Laser range finder system 110 inFIG. 42 can use a time of flight calculator 455 and an intensitycalculator 460 in FIG. 4A to measure one or more aspects of reflectedlaser pulses from the set of test locations 4320, thereby generating aset of test data 4330, including a set of ranges 4333 and a set ofreflection intensities 4336.

In several embodiment of the scan planning method a set of rules (e.g.4340) are selected and evaluated based on a subset of the test data. Theset of rules 4340 can function to convert the test data 4330 to a set ofresults 4360, such as a binary value (e.g. satisfied, unsatisfied, TRUEor FALSE) or analog values (e.g. a measure of the change at one or moretest location relative to a previous time or a measure of the differencein range between neighboring test locations). Some rules (e.g. 4351,4352, 4355) can be test vectors; a criterion operable to satisfied orunsatisfied (i.e. determined to be true or false) based on one or moreaspects of reflections from laser pulses from a subset of the set oftest locations. For example, rule 4351 is a test vector that issatisfied if the range at test location X1 is less than 10 meters.Similarly rule 4352 is a test vector that is satisfied if the test dataset entry for the range at X1 is greater than 9 meters. Location X1 ison the rear bumper of vehicle 4420 in FIG. 0.44A and rules 4351 and 4352can only be simultaneously satisfied if there is an object within a 9-10meter range. Hence test vectors 4351 and 4352 can function as test thatwhen satisfied indicate that vehicle 4420 is within 9-10 meters ofsystem 110 in FIG. 42. For example, rule 4357 states that the density ina first region during a main scan should be equal to twice the change inmeasured range in a region defined by vertices X7, X8, X9 and X10. Henceif the change in range in the region bounded by the vertices X7-X10 issmall then the density of ranging measurements selected during thesubsequent main scan according to the set of laser steering parametersis also low.

Several subsets of rules can test the location of a feature (e.g.feature 4350 a localizing a boundary of a first car 4420 in FIG. 44A andfeature 4350 b localizing the boundary of a second car in FIG. 44A).Rules can be a transfer functions (e.g. 4357) that define a relationshipbetween and input subset of the test data and a second set of lasersteering parameters. An exemplary second set of laser steeringparameters 4370, can include parameter 4380 a to generate a region witha higher density of laser pulses than a second region (e.g. a normaldensity region generated by laser steering parameter 4380 b).

FIG. 44A illustrates an exemplary embodiment wherein a steerable laserassembly 120 dynamically steer a laser beam according to a first set oflaser steering parameters (e.g. 4310 in FIG. 43) to generate test datafrom a set of test locations including 4410 a, 4410 b, 4410 c, 4410 d,4410 e, 4410 f, 4410 g. The laser range finder 110 can be on a vehiclethat is moving at a relatively constant speed relative to vehicle 4420and 4425 in neighboring lanes. Several locations (e.g. 4410 c and 4410d) can be used to test the location of vehicle 4420 relative to the sideof a lane indicated by lane markers 4430. Hence a test vector (e.g. 4355in FIG. 43) can be evaluated to determine if vehicle 4420 has movedsignificantly closer to the edge of the lane.

In FIG. 44B and with reference to FIG. 43 vehicle 4420 is in the processof changing lanes. An exemplary ranging scan planning method, based ontest locations can firstly perform laser ranging at a set of testlocations (e.g. 4320) early in a scan to generate test data (e.g. 4330)from the test locations. In the embodiment of FIG. 44B several testvectors (e.g. 4351 and 4352) associated with the boundary feature 4350 aof vehicle 4420 are evaluated and are not satisfied, thereby providing afast indication that vehicle 4420 has moved within the FOV. Theexemplary scan planning method in FIG. 44B can generate a second set oflaser steering parameters (e.g. 4370), based on the test data from thetest locations. The second set of laser steering parameters can includea dense scan region (e.g. 4440) operable to locate the vehicle 4420, andprovide the basis for an updated set of test regions, test locations,and set of rules (e.g. 4340). In the embodiment of FIG. 44B vehicle 4425maintains a constant relative position to the laser range finder 110 andhence satisfies the associated rules (e.g. 4350 b). The second set oflaser steering parameters can generate a lower density of laser pulses(e.g. 4455 a and 4455 b) surround vehicle 4425, when the associatedrules are satisfied. For example, scan region 4450 can be a portion ofthe FOV scanned according to the second set of laser steeringparameters. Scan region 4450 can be associated with several features ofvehicle 4425 and can be associated with a subset (e.g. 4350 b) of theset of rules 4340 for evaluating the test data (e.g. 4330). Hence whenthe subset 4350 b of the set of rules is satisfied the second set oflaser steering parameters can produce a lower density of laser ranginglocations (e.g. laser pulses) in the corresponding scan region 4450.

FIG. 45A-E illustrate various aspects of a laser scan planning methodaccording to an exemplary embodiment. Turning to FIGS. 45A and 45B asteerable laser assembly can dynamically steer one or more laser beamsalong paths 4505 and 4510 inside the FOV 4520. The laser beam(s) can besteered according to a first set of laser steering parameters to travelalong paths 4505 and 4510. Paths 4505 and 4510 can be selected toperform laser ranging (e.g. discrete laser pulses) in a test region(e.g. the region between inner perimeter 4530 and outer perimeter 4535in FIG. 45B). Paths 4505 and 4510 can be selected to generate laserreflection data from a set of test locations. The set of test locations(e.g. including 4540 a and 4540 b in FIG. 45B) may not be preciselyknown before the steerable laser assembly scans. However paths 4505 and4510 can be selected to generate a set of test points with a highprobability of satisfying a set of rules at some initial time. In theexample of FIG. 45A-E vehicle 4515 can be moving from left to rightacross the FOV 4520. The average or instantaneous speed of the vehiclecan be estimated and paths 4505 and 4510 can be selected in order togenerate a set of test data from a set of test locations in FIG. 45Boperable to satisfy a set of rules based on the anticipated location ofvehicle 4515 at some later time. For example, a test vector in the setof rules can state that test location 4540 b should have a rangeconsistent with the distance to the front bumper of vehicle 4515, whiletest location 4540 a should have a longer range consistent with thebackground surrounding the vehicle. Hence a test vector can be satisfiedwhen points 4540 a and 4540 b have a difference in range consistent withthe boundary of vehicle 4515. In this way the first set of lasersteering parameters can be modified based on the expected position ofvehicle 4515 to generate a small set of up-to-date test locations (e.g.1000 locations). A corresponding set of rules can then be evaluated toplan a larger scan using a second set of laser steering parameters.

In FIG. 45C vehicle 4515 has changed velocity. Therefore the test datacorresponding to the set of test locations (i.e. based on the predictedspeed of the vehicle) can fail to satisfy a number of the correspondingrules. For example, the previous test vector requiring a difference inrange between points 4540 a and 4540 b may fail. It can be appreciatedthat the test vector can be obtained prior to generating the test datafrom the set of test locations and subsequently applied to severalsubsets of the test data to try to achieve satisfaction of the testvector. For example, one embodiment of the scan planning method couldobtain a set of rules prior to gathering test data and later determineif any two laser ranging locations in a subset of the set of testlocations can satisfy one or more of the test vectors. For example, atest vector stipulating a change in range at front bumper of vehicle4515 could be evaluated several times with a first location from a testregion expected to be within the vehicle boundary and a second locationfrom a test region expected to be outside the vehicle boundary.

FIG. 45D illustrates a scan region 4550 that is scanned in a densemanner (e.g. drawing a laser beam through region 4550 at a slower speedor generating a higher laser pulse rate). Scan region 4550 can begenerated according to a second set of laser steering parameters. Scanregion 4550 can correspond to specific failing rules in a set of rulesapplied to the data from the set of test locations (e.g. 4540 a and 4540b) in FIG. 45C. In this way the small set of test locations scanned in adynamically steered manner can determine in part a subsequent dense scanof a region (e.g. region 4550).

In one aspect of several embodiments scan region 4550 can be correlatedwith the location of vehicle 4515 and thereby the locations (i.e.directions) in the field of view associated with the vehicle can bescanned in rapid succession Scanning the points associated with vehicle4515 in a concentrated manner instead of spreading these points over thecourse of uniform scan reduces the impact of the vehicles motion on scandata. These motion artifacts associated with scanning a moving object ina field of view are one of the largest sources of location error in anon-dynamically steered laser scan. For example, consider that vehicle4515 is moving at 30 miles per hour from left to right across the fieldof view. During the course of a 10 Hz (i.e. 100 ms) uniform scan of theFOV, vehicle 4515 has moved 1.4 meters. This motion error makes itdifficult to estimate the exact boundaries of vehicle 4515. Anembodiment of the proposed scan planning method could identify a subsetof locations associated with the vehicle, based in part on the test dataand scan these in a sequential manner. In general therefore embodimentsof the disclosed methods can identify moving objects based on evaluatingtest vectors and thereby generate a second set of laser steeringparameters to perform ranging at a scan set of locations in a sequencethat reduces motion artifacts (e.g. distortion due to motion of thescanned object). Locations outside of the scan region 4550 can bescanned with a lower density of laser ranging locations (e.g. 4540 c).FIG. 45E illustrates that following a dense scan of scan region 4550 anew set of updated test locations 4550 can be generated. In someembodiments many of the same rules can be applied to test data form theupdated set of test locations by updating the subset of test locationsused to evaluate each rule in the set of rules.

FIG. 46A illustrates a simple example where a steerable laser assemblyscans a laser beam in a uniform pattern to generate a 10×10 grid of testlocations in a FOV. The range measured 4610 at each of the 100 testlocations can be compared with an equivalent location in a previous scan(e.g. a large scan of 200,000 points). The change in range at each testlocation (e.g. location 4620) can be calculated and used as a guide todistribute laser scan locations in a subsequent non-uniform densityscan. For example, test location 4620 indicates a large change in rangerelative to a previous scan and can therefore receive a higher densityof laser ranging measurements in comparison to a region where the testlocation (e.g. 4640) indicates little change.

FIG. 46B illustrates a simpler situation, where the change in range iscalculated for a set of test location and a set of rules can be used toguide a larger scan. In FIG. 46B the test locations (e.g. test location4620) are scanned in a dynamically steered manner, in comparison to theuniformly steered manner of FIG. 46A. In both FIG. 46A and FIG. 46B aset of test data is gathered before a large scan from a small number oftest points (e.g. 100 in FIG. 46A and 11 in FIG. 46B) can be used toplan the larger scan to a more productive manner.

FIG. 47 illustrates a method for generating a laser ranging scan with anon-uniform spatial distribution of laser ranging measurements based atleast in part on test locations. At step 4710 a steerable laser assemblysteers one or more laser beams in a field of view, according to a firstset of laser steering parameters, and thereby generating test data for aset of test locations.

The test data is based on one or more aspects of reflected laser lightfrom the set of test locations. At step 4720 the test data is processed,according to a set of rules and thereby generate a second set of lasersteering parameters. At step 4730 the steerable laser assemblydynamically steers at least one laser beam, based at least in part onthe second set of laser steering parameters, thereby generating a scanset of laser pulses, wherein the dynamic steering generates at least inpart a first region of the field of view with a higher density of laserpulses than at least one other region of the field of view, based atleast in part on the test data.

FIG. 48A illustrates a method 4800 for performing a laser ranging scan(e.g. a main scan) with non-uniform spatial distribution of laserranging measurements based at least in part on analyzing laserreflections from a set of test locations. At step 4805 a set of featuresare selected. At step 4810 a set of test regions are selected. At step4815 a first set of laser steering parameters are selected. At step 4820a laser beam is dynamically steered according to the first set of lasersteering parameters to generate a set of test laser pulses at a set oftest locations. At step 4825 test data is received, corresponding to oneor more aspects of reflected laser pulses at the set of test locations.At step 4830 a set of test vectors are selected. At step 4835 the set oftest vectors are evaluated based on the test data from the set of testlocations thereby generating a set of test results. At step 4840 one ormore dense scan regions are selected to receive a higher density of scanlocations in a subsequent laser ranging scan. At step 4845 a second setof laser steering parameters are generated, based at least in part onthe set of test results. At step 4850 the laser is dynamically steeredaccording to the second set of laser steering parameters, therebygenerating a scan set of laser pulses at a set of scan locations. Atstep 4855 the set of features are updated. At step 4860 the set of testvectors are updated. At step 4865 the set of test regions are updated.

FIG. 48B illustrates a method 4802 for performing a laser ranging scan(e.g. a main scan) with non-uniform spatial distribution of laserranging measurements, based at least in part on analyzing laserreflections from set test locations. In comparison to method 4800 method4802 can be used to interrupt the main scan (i.e. the scan based on thesecond set of laser steering parameters) when an interrupt criterion issatisfied and remeasure the set of test locations according to the firstset of laser steering parameters. Method 4802 thereby provides forscanning and measuring the set of test locations several timesthroughout a main scan of the set of scan locations. For example, method4802 can periodically reassess important locations and reevaluate theset of test vectors during the process of scanning a more mundane regionof space (e.g. an unpopulated stretch of road). Hence method 4802provides a way to implement the competing goals of quickly identifyingchanges in important locations and scanning the whole FOV, includingmany mundane areas, for signs of new important objects and locations. Inone aspect method 4802 provides a means to arbitrate between thecompeting goals of performing a comprehensive main scan whileperiodically “cutting to the chase” and searching for important changes.

At step 4854 a main scan already in progress is interrupted based onsatisfaction of an interrupt criterion. The interrupt criterion can be avalue reached by an interrupt timer (e.g. the timer could satisfy theinterrupt criterion every 20 milliseconds), or a number of scan pointssince the last interrupt (e.g. interrupt every 20,000 scan pulses aregenerated during the main scan). The interrupt criterion can also bebased on an aspect of the data gathered during the main scan. Forexample, the main scan can be initiated according to the second set oflaser steering parameters. Initial ranging data gathered during the mainscan can indicate considerable range variations relative to a previousscan. Step 4854 can thereby satisfy interrupt criterion based on ameasure of the variation and trigger method 4802 to quickly re-measurethe set of test locations and update the second set of laser steeringparameters.

At step 4847 the second set of laser steering parameters can be updatedbased on set of test results from the evaluated test vectors. At step4852 a main scan of the field of view can be started or resumed based onthe second set of laser steering parameters. For example, the second setof laser steering parameters can define a path (e.g. 4505 in FIG. 45A)along which steerable laser assembly 120 in FIG. 44A is dynamicallysteered. The path may take 50 milliseconds to traverse completely. Atstep 4852 a main scan that has traversed the first 20% of the path canresume and complete another 20% of the path defined in the second set oflaser steering parameters before interrupting at step 4854 and gatheringupdated laser reflections form the set of test locations.

One challenge with laser ranging systems on autonomous vehicles (e.g.self-driving cars) is the need to perform laser ranging at longdistances. For example, a laser pulse generated by range finder system110 in FIG. 44A takes approximately 1.3 microseconds to reflect from anobject 200 meters away. A non-dynamically steered laser can thereforeonly generate 750,000 ranging measurements per second. Such anon-dynamically steered laser with a 10 Hz scan rate (e.g. scanning theentire FOV 10 times per second) could only produce 75,000 rangingmeasurements per second.

Method 4802 can increase the number of ranging measurement whilemaintaining the 200 m maximum. Method 4802 can interrupt the main scanat step 4854 if ranging measurements indicate reflections at or beyond200 m. Method 4802 can reevaluate test data from the set of testlocations and thereby update the second set of laser steering parametersat step 4847 to move the laser beam faster, thereby producing a modified(e.g. lower) density of ranging measurements. In this way method 4802(in some cases combined with variable pulse generation rate) canincrease or decrease the pace of the main scan. For example, system 110in FIG. 44A can have a target to generate 100,000 measurements within100 milliseconds in a main scan. A disproportionate amount of time canbe spent waiting for reflections from objects at the edge of thedetection range of system 110. Hence method 4802 can interrupt andmodify the second set of laser steering parameters if it falls behindschedule.

FIG. 5 illustrates several components of laser range finder 510 operableto perform several embodiments of the scan planning method. System 110can contain a processing subassembly 510, a steerable laser assemblysubassembly 505 and a communication link 530 for linking the processingand steerable laser assemblies. Processing subassembly 520 can includeone or more processors (e.g. sensor data processor 475 in FIG.) one ormore transceivers (e.g. including receivers 415 and transmitters 470)such as Ethernet, RS485, fiber optic, Wi-Fi, Bluetooth, CANBUS or USBtransceivers. Processing subassembly 520 can also include acomputer-readable storage medium (e.g. flash memory or a hard diskdrive) operable to store instructions for performing one or moreembodiments of methods 4700 in FIG. 47, 4800 in FIG. 48A or 4802 in FIG.48B. Steerable laser assembly 505 can include one or more lasergenerator 420 and a laser positioner 430 to steer a laser beam at one ormore locations in the FOV based on the laser steering parameters. Laserpositioner 430 can include one or more optical delay lines, acoustic orthermally based laser steering elements. In a solid stateelectronically-steered laser ranging subassembly laser positioner canfunction to receive instructions based on laser steering parameters andthereby delay portions of a laser beam (i.e. create a phase differencebetween copies of the laser beam) and then combine the portions of thelaser beam to form an output beam positioned in a direction in the FOV.A mechanical laser positioner 430 can be a mirror and mirror positioningcomponents operable to receive input (e.g. PWM input to a steeper motor)based on laser steering parameters and thereby steer the mirror toposition a laser in a direction in the FOV. Steerable laser assembly 505can also include data acquisition components 540, such as reflectiondetector 450, time of flight calculator 455 and light intensitycalculator 460 in FIG. 4A. Steerable laser assembly 505 can include oneor more transceivers (e.g. receivers 415 and transmitters 470 in FIG.4A) such as Ethernet, RS485, fiber optic, Wi-Fi, Bluetooth, CANBUS, orUSB transceivers. Communication link 530 can be a wired link (e.g. anEthernet, USB or fiber optic cable) or a wireless link. Communicationlink 530 can transfer laser steering parameters or equivalentinstructions from the processing subassembly 520 to the steerable laserassembly 505. Communication link can transfer ranging data from thesteerable laser assembly to the processing subassembly 520.

When operable linked to steerable laser assembly 505 the processingsubassembly 520 can perform one or more embodiments of the rangingscanning planning method of the present disclosure. Specificallyprocessing subassembly 510 can generate and transmit a first set oflaser steering parameters to steerable laser assembly 505, wherein thefirst set of laser steering parameters are operable to cause thesteerable laser assembly 505 to dynamically steer one or more laserbeams within a field of view and thereby generate a test set of laserpulses at a set of test locations in the field of view. Secondlyprocessing subassembly 520 can receive from the steerable laser assemblytest data comprising one or more aspect of reflected light from laserpulses at the set of test locations. Thirdly, processing subassembly 520can select a set of test vectors, each test vector in the set of testvectors being a criterion operable to be evaluated based on one or moreaspects of reflected laser pulses from a subset of the set of testlocations. Fourthly, processing subassembly 520 can evaluate each testvector in the set of test vectors based on at least some of the testdata, and thereby at least in part generating a set of test resultscorresponding to the set of test vectors. Finally, processingsubassembly 520 can generate a second set of laser steering parametersbased on the set of test results, and thereby instruct the steerablelaser assembly to perform a main scan, including dynamically steering alaser beam with the steerable laser assembly to generate a non-uniformlyspaced scan set of laser pulses, based at least in part on the resultsof the test vectors.

Adaptive Laser Scan Planning Based on Time of Flight

A growing area for LIDAR application is autonomous passenger vehicles(e.g. autonomous cars and trucks). At typical highway speeds (e.g. 65mph) there is a need to provide range measurements up to 200 metersahead of the vehicle. The maximum range of a LIDAR system is determinedin part by the sensitivity of the reflection detector 450 in FIG. 4A andin part by how long the LIDAR is willing to wait for a reflection. ALIDAR designed with a 200 m maximum range must wait up to 1.3microseconds for a laser pulse to travel a round trip distance of 400 mto and from a object at maximum range. At 200 m maximum range a singlelaser/detector pair can perform a maximum of 750,000 measurements persecond. Some LIDAR models (e.g. HDL-64E from Velodyne LIDARs of MorganHill, Calif.) use multiple laser/detector pairs each focused on aparticular elevation angle to produce more measurements.

Another approach to increasing the measurement rate (e.g. measurementsper scan of the FOV) while maintaining a maximum range (e.g. 200 m) isto use variable laser pulse timing instead of periodic laser pulsetiming. For example, a LIDAR system designed for 200 m maximum range mayhave a maximum pulse spacing of 1.3 microseconds, but many transmittedlaser pulses can be reflected much earlier from objects closer than themaximum range. Accordingly the laser can be configured to produce a newlaser pulse at the lesser of: a) every 1.3 microseconds, or b) when areflection is detected. Variable pulse timing can ensure that the LIDARperforms a minimum of 750,000 measurements with some unknown maximumbased on the arrangement of objects in the FOV. While this is animprovement, a LIDAR with variable pulse timing can still suffer from aslow measurement rate when performing measurements in large portions ofthe FOV without objects. A non-steerable LIDAR (e.g. a rotating LIDARwith constant angular velocity) proceeds on a predetermined path withinthe FOV and can do little to solve the problem of encountering largeunfilled portions of the FOV that slow the measurement rate.

Recent advancements in dynamically steerable LIDAR (e.g. electronicallysteerable LIDAR) provide the ability to dynamically distributemeasurement locations in the FOV. For example, when a region of the FOVis encountered with reflections close to or beyond the maximum range thedensity of measurement points can be decreased, thereby enabling theLIDAR to complete the can in a reasonable time (e.g. a target time) orto achieve a target number of measurements within some or all of theFOV. Therefore dynamic-steering provides the basis for a LIDAR to ensurea level of service (e.g. 10 scans of the FOV per second, or a minimum of100,000 measurements per scan).

A non-steerable LIDAR can provide a consistent level of service (e.g.one scan of the FOV every 100 ms). A dynamically steerable LIDAR canprovide a similar or higher level of service at a lower cost bydynamically steering more cost effective hardware. In one embodiment amethod is disclosed to perform a laser ranging scan in which the dynamicsteering of a laser is adapted, based on time of fight measurements fromthe scan, in order to complete the scan in a time target.

In other embodiments a computer implemented method can select aservice-level criterion for a laser ranging scan of a portion of a FOV.The service-level criterion can be a time target for completing the scanor a target number of measurements within the scan. The method cancommence the laser ranging scan according to a set of laser steeringparameters. At some time after commencing the scan the method can modifythe set of laser steering parameters based on time-of-flightmeasurements from the scan and then continue the scan according to themodified set of laser steering parameters, such that at the end of thescan the service-level criterion is satisfied.

In yet other embodiments, the method can select a service-levelcriterion indicative of a level of service offered by laser range finder(e.g. maximum scan time or minimum number of measurement points) and canalso select a completion criterion for the scan (e.g. when a particularpath has been traversed by the laser, or when a sweep of some or all ofthe FOV is complete). The adaptive laser scan planning method can modifyan initial set of laser steering parameters throughout the course of alaser scan, based on the ranging data received, such that themodifications ensure the completion criterion and the service-levelcriterion are simultaneously satisfied at some time (e.g. at or beforethe target time).

An exemplary adaptive LIDAR (e.g. a laser range finder implementing theadaptive laser scan planning method) can be dynamically-steerable andhave a time target to complete a scan of a FOV. During the course of thescan the adaptive LIDAR can adapt the measurement distribution, based inpart on the time-of-flight data from the surroundings to achieve thetime target. For example, an adaptive LIDAR can have a time target of100 ms to scan a FOV (e.g. 360 degrees azimuth at a single elevationangle). At the midpoint of the scan (e.g. at 180 degrees) the adaptiveLIDAR can recognize that it is behind schedule to meet the time target.This may be due to a portion of the FOV with reflections arriving closeto or beyond the maximum measurement time (e.g. 1.3 microsecondscorresponding to 200 m max range). Hence the exemplary adaptive LIDARcan alter the planned measurement distribution in the remainder of thescan to meet the time target.

Associated with many tasks (e.g. constructing a building or completing astandardized test) there can be a completion criterion and aservice-level criterion. The completion criterion can be a test todetermine if the task is completed (e.g. are all the questions on a testanswered?). A service-level criterion can be a test of the service-levelassociated with the completed task (e.g. was the test completed in theallotted time, or were at least 80% of the answers to the questionscorrect?).

A dynamically steerable laser range finder can dynamically position alaser beam to perform intelligent and in-depth investigation of parts ofthe FOV based on non-uniformly distributed measurement locations.However a dynamically steerable laser range finder can be of limited useif it spends too much time investigating object boundaries or far awayobjects (e.g. requiring long measurement times) and consequently doesnot complete a scan (e.g. fails to scan a portion of the FOV) takes toolong to complete a scan.

In several embodiments a computer implemented method is providedoperable to be performed by a laser ranging system to modify lasersteering parameters throughout the course of a scan to adapt the futuredistribution of measurements such that the scan satisfies aservice-level criterion upon completion of the scan (i.e. satisfies acompletion criterion). Hence the laser range finder can dynamicallyadapt to the surroundings.

Turning to FIG. 49 a laser range finder 110 includes a steerable laserassembly 120 operable to dynamically steer a laser beam within FOV 4910.According to an embodiment of the adaptive laser scan planning method acompletion target or criterion can be selected (e.g. starting at anazimuthal angle of 0 degrees the completion target can be to complete apath to an azimuthal angle of 180 degrees). A service-level criterioncan also be selected, For example, that the scan be competed in no morethan 100 milliseconds or completed with no fewer than 100,000 points. Aservice-level criterion can also specify a required minimum measurementdensity (e.g. number of measurements per unit angle in the azimuth andelevation planes). FOV 4910 includes several interesting objects such asperson 4915 and vehicle 4920. Between the interesting objects is a largeregion where laser reflections do not occur and therefore theperformance of system 110 is impacted by waiting for reflections that donot arrive. According to an embodiment of the adaptive laser scanplanning method, laser range finder 110 can scan a laser beam along apath (e.g. 4925) and thereby generate a plurality of laser rangingmeasurements. The dynamically steerable nature of steerable laserassembly 120 enables regions with a high density of laser pulses (e.g.laser pulses 4930 and 4940) and regions with a low density of laserpulses e.g. 4937. Additionally laser pulses can have a dynamicallyselected spot size (e.g. large spot size 4935). One feature of theexemplary adaptive laser scan planning method is that certain aspects ofpath 4925 are unknown at the beginning of the scan (e.g. the exact laserpulse density, spot sizes or pulse sizes). These aspects are adaptivelyselected in order to satisfy the service-level criterion at thecompletion of the scan. For example, the exact laser pulse density at apoint in the scan can be selected based on whether the scan is ahead ofschedule or behind schedule, relative to a target completion time.

Graph 4942 illustrates the progress of the scan (i.e. the azimuthallocation of the laser beam as it scans from a start point to 0 degreesto the completion point of 180 degrees) versus elapsed time since thestart of the scan. Line 4943 illustrates the time elapsed for a uniformscan of the FOV such that upon satisfaction of the completion criterion(e.g. reaching 180 degrees azimuth) the service-level criterion (e.g.performing the scan within target time 4945) is also satisfied. Line4944 illustrates the actual performance of laser range finder 110 as itscans the FOV while modifying a set of laser steering parameters inorder to complete the scan while satisfying the service-level criterion.The scan begins at azimuth angle 4946. Between azimuth angle 4946 and4950 the scan encounters vehicle 4920 and uses an initial set of lasersteering parameters to instruct steerable laser assembly 120 to generatea default density of laser pulses (e.g. laser pulse 4930). At time 4955the elapsed time is marginally behind schedule (i.e. progress line 4944is above line 4943). Between azimuth 4950 and 4960 laser pulses do notreflect form objects within the maximum range of the laser range finder110. Hence measurements in range 4950 to 4960 are slow and the scanfalls further behind schedule as illustrated by elapsed time 4965. Theexemplary adaptive laser scan planning method reacts by modifying theset laser steering parameters to increasing the speed along path 4925,increasing the step size in the azimuth direction and increase the spotsize. Increasing the speed and step size has the effect of decreasingthe measurement density in the center region 4937. Increasing the spotsize has the effect of providing more laser energy to help identifyreflections from objects close to the maximum range. Steerable laserassembly 120 then steers one or more laser beams according to themodified set of laser steering parameters and between azimuth 4960 and4970 the scan proceeds more quickly such that the scan is ahead ofschedule at 4975. Between azimuth 4970 and the completion angle 4980(e.g. 180) laser range finder 110 encounters another interesting object,person 4915. System 110 can be aware that it is ahead of schedule andclose to the end of the scan and can therefore modify the laser steeringparameters for a second time to increase the density of measurementpoints (e.g. laser pulse 4940), thereby completing the scan whilesatisfying the service-level criterion.

In another embodiment, a set of laser steering parameters can begenerated or modified after commencing a laser ranging scan and based onthe target time. For example, a laser steering parameter may originallycalculate a density of 1 laser pulse per 1 degree of angular range for adense scan region, based on a time target of 100 milliseconds for thescan. During the scan the laser range finder may identify that the scanis behind schedule and can modify the laser steering parameter to 1laser pulse every 2 degrees in order to complete the laser ranging scanwithin the target time.

FIG. 50 illustrates an exemplary adaptive laser scan planning method5000. At step 5010 method 5000 begins. At step 5020 a service-levelcriterion for a laser ranging scan of at least some a field of view isselected. At step 5020 a completion criterion for the scan can also beselected. Exemplary service-level criteria include a target time tocomplete the scan, a target number of measurements, a target laser pulsedensity (e.g. number of measurement points per unit of angle in theFOV). Exemplary completion criteria can include reaching the end of apath (e.g. a path defined in the initial set of laser steeringparameters), reaching an endpoint location in the FOV, completing a scanof a defined portion of the FOV. At step 5030 a set of laser steeringparameters is selected.

At step 5040 at least one laser beam is dynamically steered with asteerable laser assembly, according to the set of laser steeringparameters and thereby generates laser pulses at a first set oflocations in the field of view. At step 5050 the time-of-flight of oneor more reflections from one or more laser pulses at a first location inthe first set of locations is measured. At step 5060 the set of lasersteering parameters is modified based at least in part on thetime-of-flight of the one or more reflections of the one or more laserpulses at the first location, wherein the modified set of laser steeringparameters function to ensure the service-level criterion is satisfiedupon completion of the laser ranging scan. At step 5070 the at least onelaser beam is dynamically steered with the steerable laser assembly,according to the modified set of laser steering parameters and therebycompletes the laser ranging scan, such that the service-level criterionis satisfied upon completion of the laser ranging scan. At step 5080method 5000 ends.

While the above description contains many specificities, these shouldnot be construed as limitations on the scope of any embodiment, but asexemplifications of various embodiments thereof. Many otherramifications and variations are possible within the teachings of thevarious embodiments. Thus the scope should be determined by the appendedclaims and their legal equivalents, and not by the examples given.

Any of the methods (including user interfaces) described herein may beimplemented as software, hardware or firmware, and may be described as anon-transitory computer-readable storage medium storing a set ofinstructions capable of being executed by a processor (e.g., computer,tablet, smartphone, etc.), that when executed by the processor causesthe processor to control perform any of the steps, including but notlimited to: displaying, communicating with the user, analyzing,modifying parameters (including timing, frequency, intensity, etc.),determining, alerting, or the like.

When a feature or element is herein referred to as being “on” anotherfeature or element, it can be directly on the other feature or elementor intervening features and/or elements may also be present. Incontrast, when a feature or element is referred to as being “directlyon” another feature or element, there are no intervening features orelements present. It will also be understood that, when a feature orelement is referred to as being “connected”, “attached” or “coupled” toanother feature or element, it can be directly connected, attached orcoupled to the other feature or element or intervening features orelements may be present. In contrast, when a feature or element isreferred to as being “directly connected”, “directly attached” or“directly coupled” to another feature or element, there are nointervening features or elements present. Although described or shownwith respect to one embodiment, the features and elements so describedor shown can apply to other embodiments. It will also be appreciated bythose of skill in the art that references to a structure or feature thatis disposed “adjacent” another feature may have portions that overlap orunderlie the adjacent feature.

Terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.For example, as used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, steps, operations, elements, components, and/orgroups thereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items and may beabbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if a device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus, the exemplary term “under” can encompass both anorientation of over and under. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly”, “downwardly”, “vertical”, “horizontal” and the like are usedherein for the purpose of explanation only unless specifically indicatedotherwise.

Although the terms “first” and “second” may be used herein to describevarious features/elements (including steps), these features/elementsshould not be limited by these terms, unless the context indicatesotherwise. These terms may be used to distinguish one feature/elementfrom another feature/element. Thus, a first feature/element discussedbelow could be termed a second feature/element, and similarly, a secondfeature/element discussed below could be termed a first feature/elementwithout departing from the teachings of the present invention.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising” means various components can be co jointlyemployed in the methods and articles (e.g., compositions and apparatusesincluding device and methods). For example, the term “comprising” willbe understood to imply the inclusion of any stated elements or steps butnot the exclusion of any other elements or steps.

In general, any of the apparatuses and methods described herein shouldbe understood to be inclusive, but all or a sub-set of the componentsand/or steps may alternatively be exclusive, and may be expressed as“consisting of” or alternatively “consisting essentially of” the variouscomponents, steps, sub-components or sub-steps.

As used herein in the specification and claims, including as used in theexamples and unless otherwise expressly specified, all numbers may beread as if prefaced by the word “about” or “approximately,” even if theterm does not expressly appear. The phrase “about” or “approximately”may be used when describing magnitude and/or position to indicate thatthe value and/or position described is within a reasonable expectedrange of values and/or positions. For example, a numeric value may havea value that is +/−0.1% of the stated value (or range of values), +/−1%of the stated value (or range of values), +/−2% of the stated value (orrange of values), +/−5% of the stated value (or range of values), +/−10%of the stated value (or range of values), etc. Any numerical valuesgiven herein should also be understood to include about or approximatelythat value, unless the context indicates otherwise. For example, if thevalue “10” is disclosed, then “about 10” is also disclosed. Anynumerical range recited herein is intended to include all sub-rangessubsumed therein. It is also understood that when a value is disclosedthat “less than or equal to” the value, “greater than or equal to thevalue” and possible ranges between values are also disclosed, asappropriately understood by the skilled artisan. For example, if thevalue “X” is disclosed the “less than or equal to X” as well as “greaterthan or equal to X” (e.g., where X is a numerical value) is alsodisclosed. It is also understood that the throughout the application,data is provided in a number of different formats, and that this data,represents endpoints and starting points, and ranges for any combinationof the data points. For example, if a particular data point “10” and aparticular data point “15” are disclosed, it is understood that greaterthan, greater than or equal to, less than, less than or equal to, andequal to 10 and 15 are considered disclosed as well as between 10 and15. It is also understood that each unit between two particular unitsare also disclosed. For example, if 10 and 15 are disclosed, then 11,12, 13, and 14 are also disclosed.

Although various illustrative embodiments are described above, any of anumber of changes may be made to various embodiments without departingfrom the scope of the invention as described by the claims. For example,the order in which various described method steps are performed mayoften be changed in alternative embodiments, and in other alternativeembodiments one or more method steps may be skipped altogether. Optionalfeatures of various device and system embodiments may be included insome embodiments and not in others. Therefore, the foregoing descriptionis provided primarily for exemplary purposes and should not beinterpreted to limit the scope of the invention as it is set forth inthe claims.

The examples and illustrations included herein show, by way ofillustration and not of limitation, specific embodiments in which thesubject matter may be practiced. As mentioned, other embodiments may beutilized and derived there from, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. Such embodiments of the inventive subject matter maybe referred to herein individually or collectively by the term“invention” merely for convenience and without intending to voluntarilylimit the scope of this application to any single invention or inventiveconcept, if more than one is, in fact, disclosed. Thus, althoughspecific embodiments have been illustrated and described herein, anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

1-3. (canceled)
 4. A method comprising: obtaining a time target for alaser ranging scan of at least some of a field of view; dynamicallysteering, at least one laser beam with a steerable laser assembly,according to a set of laser steering parameters and thereby generatinglaser pulses at a first set of locations in the at least some of thefield of view; in response to processing a set of laser reflections fromthe laser pulses, generating a modified set of laser steering parametersthat functions to complete the laser ranging scan of the at least someof the field of view within the time target; dynamically steering the atleast one laser beam with the steerable laser assembly, according to themodified set of laser steering parameters and thereby completing thelaser ranging scan of the at least some of the field of view within thetime target.
 5. The method of claim 4 wherein the step of processing theset of laser reflections from the laser pulses, further comprises thestep of identifying an object in the field of view.
 6. The method ofclaim 4 wherein the step of processing the set of laser reflections fromthe laser pulses, further comprises identify an object in the field ofview, and wherein the modified set of laser steering parameters functionto configure the steerable laser assembly to non-uniformly scan theobject with a subsequent set of laser pulses during the laser rangingscan.
 7. The method of claim 4 wherein the step of processing the set oflaser reflections from the laser pulses, further comprises identifyingan object in the field of view and wherein the modified set of lasersteering parameters function to non-uniformly distribute a second set oflaser pulses in the field of view based on the object in the field ofview.
 8. The method of claim 4 wherein the step of processing the set oflaser reflections from the laser pulses, further comprises identifying alocation of an object in the field of view and wherein the modified setof laser steering parameters further functions to non-uniformlydistribute a new set of laser pulses in the field of view, based on thelocation of the identified object in the field of view.
 9. The method ofclaim 4 wherein the step of processing the set of laser reflections fromthe laser pulses, further comprises identifying a portion of the fieldof view containing an object, and wherein the modified set of lasersteering parameters further function to non-uniformly distribute asubsequent set of laser pulses in the field of view based on the portionof the field of view containing the object.
 10. The method of claim 4wherein the processing of the laser reflections further comprising thestep of determining that the set of laser steering parameters will notcomplete the laser ranging scan of the at least some of the field ofview in the target time.
 11. A method comprising: obtaining a timetarget for a laser range finder to complete a laser ranging scan of afirst portion of a field of view; selecting a set of laser steeringparameters; configuring a steerable laser assembly in the laser rangefinder with the set of laser steering parameters and thereby dynamicallysteering, at least one laser beam with the steerable laser assembly togenerate a first set of laser pulses at a first set of locations in thefirst portion of the field of view as part of the laser ranging scan;detecting with a laser detector in the laser range finder a laserreflection corresponding to the first set of the laser pulses;processing the laser reflection to calculate a time of flightcorresponding to the laser reflection; generating, based at least inpart on the time of flight, a modified set of laser steering parametersthat functions to reconfigure the steerable laser assembly to completethe laser ranging scan of the first portion of the field of view withinthe time target; and dynamically steering the at least one laser beamwith the steerable laser assembly, according to the modified set oflaser steering parameters and thereby completing the laser ranging scanof the first portion of the field of view within the time target. 12.The method of claim 11 wherein the set of laser steering parametersconfigures the steerable laser assembly to generate the first set oflaser pulses at a first laser pulse rate and wherein the modified set oflaser steering parameters reconfigures the steerable laser assembly togenerate a second set of laser pulses at a second laser pulse ratedifferent from the first laser pulse rate, and wherein the second laserpulse rate functions to complete the laser ranging scan of the field ofview within the target time.
 13. The method of claim 3 wherein the setof laser steering parameters configures the steerable laser assembly tosteer the at least one laser beam at a first angular velocity in thefield of view and wherein the modified set of laser steering parametersreconfigures the steerable laser assembly to steer the steerable laserassembly with a second angular velocity different from the first angularvelocity, and wherein the second angular velocity functions to completethe laser ranging scan of the field of view within the target time. 14.A method comprising: obtaining a time target for a laser ranging scan ofa field of view; selecting a set of laser steering parameters; steering,at least one laser beam with a steerable laser assembly, according tothe set of laser steering parameters and thereby generating a first setof laser pulses at a first set of locations in the field of view;measuring for each of a set of laser reflections from the first set oflaser pulses a corresponding time of flight; in response to processingfor each of the set of laser reflections the corresponding time offlight, modifying the set of laser steering parameters such that themodified set of laser steering parameters function to provide that thelaser ranging scan will be completed within the target time; dynamicallysteering the at least one laser beam with the steerable laser assembly,according to the modified set of laser steering parameters and therebycompleting the laser ranging scan of the field of view within the targettime.
 15. The method of claim 14 wherein the set of laser steeringparameter configured the steerable laser assembly to steer the at leastone laser beam with a first angular velocity; and wherein the modifiedset of laser steering parameters configures the steerable laser assemblyto steer the at least one laser beam with a second angular velocity thatis greater than the first angular velocity.
 16. The method of claim 14wherein the step of processing for each of the set of laser reflectionsthe corresponding time of flight identifies that the the steerable laserassembly will not complete the laser ranging scan within the target timeusing the set of laser steering parameters.
 17. The method of claim 14wherein the set of laser reflections comprises at least 20 laserreflections.
 18. The method of claim 14 wherein the set of laser pulseshave a first density in the field of view and wherein the step ofdynamically steering the at least one laser beam with the steerablelaser assembly, according to the modified set of laser steeringparameters further comprises the step of generating a new set of laserpulses with a second density in the field of view that is greater thanthe first density.
 19. The method of claim 14 wherein the set of laserpulses have a first density in the field of view and wherein the step ofdynamically steering the at least one laser beam with the steerablelaser assembly, according to the modified set of laser steeringparameters further comprises the step of generating a newset of laserpulses with a second density in the field of view that is less than thefirst density.